Ophthalmologists

Ophthalmologists are medical doctors who specialize in the anatomy, physiology and diseases of the eye. Since they perform eye operations, they are considered to be both medical and surgical specialists.

1,222 Questions
Ophthalmologists

How do you shake your eyes?

It's not an easy thing to explain. You start practicing by looking at your finger or nose right in front of your face. Or you could just go cross eye. If you do this really well and hard you should see a shaking world in double.(Two of everything shaking.)

If this doesn't work for you, you could try this more confusing but more accurate way.

Look left,

Look right,

Look up,

Look down,

Look left with right eye and right with left eye,

Reverse this procedure,

look up with right eye and down with left eye,

Look north then south then east then west and then look left with left eye and right with right eye and after all this, repeat 20 times.

Eyes are now warmed up for shaking.

Go cross eye and the world should start to shake.

I hope this helped, the eye shaker doctor.

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Acronyms & Abbreviations
Ophthalmologists
Obstetricians

What does mbbs mrcgp after a doctors name mean?

mbbs/ mbchb (UK) is a medical degree from the uk mrcgp (UK) is the advanced award through assessment and examination for excellence in General practice in the UK, mbbs can also be issued from a whole range of other countries but their quality really does vary

567
Salary and Pay Rates
England
Ophthalmologists

Average salary in 1965?

11.000.

456
Parenting and Children
Pediatricians
Ophthalmologists

Why do babies sleep too much?

Newborn babies has high metabolic rate. Their cell division is very fast when compared to an adult. They need more energy for cell division. To save energy newborn babies sleeps a lot. Best new born baby clothing at kimibear!

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Ophthalmologists

Diabetes eye exams?

Description

Diabetes can harm your eyes. It can damage the small blood vessels in your retina, or the back of your eye. This is called diabetic retinopathy.

Diabetes also increases your risk of glaucoma and other eye problems.

You may not know your eyes are harmed until the problem is very bad. Your doctor can catch problems early if you get regular eye exams.

You Need Regular Eye Exams

Even if the doctor who takes care of your diabetes checks your eyes, you need an eye exam every 1-2 years by an eye doctor who takes care of people with diabetes.

If you have eye problems because of diabetes, you will probably see your eye doctor more often. Sometimes, your doctor may tell you to come less often.

You may see two different types of eye doctors:

  • An ophthalmologist is a medical doctor trained to diagnose and treat eye problems.
  • An optometrist is a health care provider trained to diagnose and treat eye problems. Many can do screening exams for damage from diabetes. Once you have eye disease caused by diabetes, you will see an ophthalmologist.
What Is a Dilated Retinal Exam?

The doctor will check your vision using a chart of random letters of different sizes. This is called the Snellen chart.

You will then be given eye drops so that the doctor can better see the back of the eye. You may feel stinging when they are first placed. You may have a metallic taste in your mouth.

To see the back of your eye, the doctor looks through a magnifying glass using a bright light. The doctor can then see areas that may be damaged by diabetes:

  • Blood vessels in the front or middle parts of the eye
  • The back of the eye
  • The optic nerve area

Another device called a slit lamp is used to see the clear surface of the eye (cornea).

After Your Eye Exam

If you had drops to dilate your eyes, your vision will be blurred for about 6 hours. It will be harder to focus on things that are near.

Sunlight can damage your eye. Wear dark glasses or shade your eyes until the drops wear off.

References

American Diabetes Association. Standards of medical care in diabetes -- 2010. Diabetes Care. 2010 Jan;33 Suppl 1:S11-61.

Reviewed By

Review Date: 11/11/2010

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Blindness and vision loss?

Definition

Blindness is a lack of vision. It may also refer to a loss of vision that cannot be corrected with glasses or contact lenses.

  • Partial blindness means you have very limited vision.
  • Complete blindness means you cannot see anything and do not see light. (Most people who use the term "blindness" mean complete blindness.)

People with vision worse than 20/200 are considered legally blind in most states in the United States.

Vision loss refers to the partial or complete loss of vision. This vision loss may happen suddenly or over a period of time.

Some types of vision loss never lead to complete blindness.

Alternative Names

Loss of vision; No light perception (NLP); Low vision; Vision loss and blindness

Common Causes

Blindness has many causes. In the United States, the leading causes are:

The type of partial vision loss may differ, depending on the cause:

  • With cataracts, vision may be cloudy or fuzzy, and there may be problems seeing shapes
  • With diabetes, vision may be blurred, there may be shadows or missing areas of vision, and difficulty seeing at night
  • With glaucoma, there may be tunnel vision and blurry vision
  • With macular degeneration, the side vision is normal but the central vision is slowly lost

Other causes include:

Home Care

The kind of home assistance you need will depend on your type of vision loss. It is important for a blind person to be able to dress, eat, function independently, and stay safe.

Many services are available that provide the training and support blind people need to function independently.

Ideas to keep things organized at home:

  • Always keep certain items in the same drawer, cabinet, table, or counter space.
  • Learn to recognize the shape of certain items, such as egg containers or cereal boxes.
  • Use plastic rings to hold pairs of socks together, whether you are washing, drying, or storing them.
  • Use small Braille labels, including a simple form of Braille called uncontracted Braille.
  • Use small raised dots, rubber bands, Velcro, or colored tape to label items that are hard to read.
  • Use caulking, raised rubber, or plastic dots to mark the "on," "bake," and certain temperature settings on the furnace thermostat and dials on stoves, toasters, the washer, and dryer.
  • Use a phone with large numbers and memorize the keypad.
  • Fold different types of paper money in a different way. For example, you can fold a $10 bill in half or double fold a $20 bill.
  • Use Braille or large-print checks.

Tips to help you get around and stay safe at home:

  • If possible, learn to use a long white cane to help you get around on your own.
  • When walking with someone else's help, grasp their arm just above the elbow. Walk slightly behind them to follow their motions.
  • Remove lose wires or cords from the floor.
  • Remove loose throw rugs.
  • Do not keep small pets in your home.
  • Fix any uneven flooring in doorways.
  • Have good lighting.
  • Put hand rails in the bathtub or shower and next to the toilet.
  • Place a slip-proof mat in the bathtub or shower.

A number of different low-vision aids can help:

  • Magnifiers
  • Technology aids to make it easier to use cell phones and computers
  • Watches made for people with low vision, or talking watches and clocks
Call your health care provider if

Sudden vision loss is always an emergency, even if you have not completely lost all vision. You should never ignore loss of vision, thinking it will get better.

Contact an ophthalmologist or go to the emergency room immediately. Most serious forms of vision loss are painless, and the absence of pain in no way diminishes the urgent need to get medical care. Many forms of vision loss only give you a short amount of time to be successfully treated.

What to expect at your health care provider's office

A complete and thorough eye examination will be performed. The treatment will depend on the cause of the vision loss.

For long-term vision loss, see a low-vision specialist, who can help you learn to care for yourself and live a full life.

References

Kraut JA. Vision rehabilitation. In: Tasman W, Jaeger Ea, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 46.

Olitsky SE, Hug D, Smith LP. Disorders of Vision. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 620.

Sterns GK, McCormick GJ. Ophthalmologic disorders. In: Duthie EH, Katz PR, Malone ML, eds. Practice of Geriatrics. 4th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 24.

Reviewed By

Review Date: 07/28/2010

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Macular degeneration - age-related?

Definition

Macular degeneration is an eye disorder that slowly destroys sharp, central vision. This makes it difficult to see fine details and read.

The disease is most common in people over age 60, which is why it is often called age-related macular degeneration (ARMD, or AMD).

Alternative Names

Age-related macular degeneration (ARMD); AMD; senile macular degeneration (SMD) is an older name that is no longer in common use.

Causes, incidence, and risk factors

The retina is at the back of the eye. It changes light and images that enter the eye into nerve signals that are sent to the brain. A part of the retina called the macula makes vision sharper and more detailed.

AMD is caused by damage to the blood vessels that supply the macula. This change also harms the macula.

There are two types of AMD:

  • Dry AMD occurs when the blood vessels under the macula become thin and brittle. Small yellow deposits, called drusen, form. Almost all people with macular degeneration start with the dry form.
  • Wet AMD occurs in only about 10% of people with macular degeneration. New abnormal and very fragile blood vessels grow under the macula. This is called choroidal neovascularization. These vessels leak blood and fluid. This form causes most of the vision loss associated with the condition.

Scientists are not sure what causes AMD. The condition is rare before age 55. It is most often seen in adults 75 years or older.

In addition to heredity, other risk factors are:

  • Caucasian race
  • Cigarette smoking
  • High-fat diet
  • Female gender
  • Obesity
Symptoms

You may not have any symptoms at first. As the disease gets worse, you may have problems with your central vision.

SYMPTOMS OF DRY AMD:

The most common symptom in dry AMD is blurred vision. Often objects in the central vision look distorted and dim, and colors look faded. You may have trouble reading print or seeing other details, but you can generally see well enough to walk and perform most routine activities.

As the disease becomes worse, you may need more light to read or perform everyday tasks. A blurred spot in the center of vision gradually gets larger and darker.

In the later stages, you may not be able to recognize faces until they are close.

SYMPTOMS OF WET AMD:

The most common early symptom of wet AMD is that straight lines appear distorted and wavy.

There may be a small dark spot in the center of vision that gets larger over time.

Central vision loss can occur very quickly. If this occurs, you will need urgent evaluation by an ophthalmologist with experience in retinal disease.

Signs and tests

You will have an eye exam. Drops will be placed into your eyes to widen (dilate) your pupils. The eye doctor will use special lenses to view your retina, blood vessels, and optic nerve.

The eye doctor will look for specific changes in the macula and blood vessels. One of the earliest findings in dry AMD are yellow deposits in the macula, called drusen.

You may be asked to cover one eye and look at a pattern of lines called an Amsler grid. If the straight lines appear wavy, it may be a sign of AMD.

Other tests that may be done include:

Treatment

If you have advanced or severe dry AMD, no treatment can restore your vision.

If you have early AMD and do not smoke, a combination of certain vitamins, antioxidants, and zinc may prevent the disease from getting worse. But it cannot give you back any vision that is already lost.

The combination is often called the "AREDS" formula. The recommended supplements contain:

  • 500 milligrams of vitamin C
  • 400 international units of beta-carotene
  • 80 milligrams of zinc
  • 2 milligrams of copper

Only take this vitamin combination if your doctor recommends it. Make sure your doctor knows about any other vitamins or supplements you are taking. Smokers should NOT use this treatment.

AREDS may also benefit you if you have a a family history and risk factors for AMD.

The supplements lutein and zeaxanthin may also be helpful, although they are not part of the AREDS formula.

If you have wet AMD, your doctor may recommend:

  • Laser surgery (laser photocoagulation) -- a small beam of light destroys the leaking, abnormal blood vessels.
  • Photodynamic therapy -- a light activates a drug that is injected into your body to destroy leaking blood vessels.
  • Special medications that prevent new blood vessels from forming in the eye (anti-angiogenesis, anti-VEGF therapy) -- drugs such as bevacizumab (Avastin) and ranibizumab (Lucentis) are injected into the eye. This is a painless process.

Low-vision aids (such as special lenses) and therapy can help you use the vision that you have more effectively, and improve your quality of life.

Close follow-up with your eye doctor is important.

  • For dry AMD, a complete eye exam should be performed by an eye specialist at least once a year.
  • People who have been treated for wet AMD need frequent, perhaps monthly, follow-up visits.

In AMD, early detection of vision changes is very important. Early detection leads to earlier treatment and often, a better outcome.

The best way to detect changes is by self-testing at home with an eye chart, called an Amsler grid. Test each eye individually with the vision correction you normally wear for reading.

Support Groups

AMD Alliance International -- (877) AMD-7171 -- www.amdalliance.org.

Expectations (prognosis)

AMD typically does not affect side (peripheral) vision. This is very important, because it means complete vision loss never occurs from this disease. This disorder results in the loss of central vision only.

Mild, dry AMD usually does not cause disabling central vision loss. However, there is no way to predict who will develop a more severe form of the disease.

Wet AMD often leads to significant vision loss.

In general, macular degeneration can cause you to lose the ability to read, drive a car, and recognize faces at a distance. Most people with this eye disease are able to eat, bathe, and perform other regular tasks without too much difficulty.

Complications

This condition may make it hard to read, work on the computer, or drive. You may need extra light or magnification to do many of your normal activities.

Calling your health care provider

If you have AMD, your health care provider may recommend that you check your vision every day on an Amsler grid. Call your provider immediately if the lines appear wavy, or you notice any other changes in your vision.

Prevention

Although there is no known way to prevent macular degeneration, lifestyle factors can reduce your risk of developing the condition:

  • Don't smoke
  • Eat a healthy diet that is high in fruits and vegetables and low in animal fat
  • Exercise regularly
  • Maintain a healthy weight

See your eye care professional regularly for dilated eye exams.

References

Benson WE. Acquired macular disease. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins;2011:chap 23.

Yanoff M, Cameron D. Diseases of the visual system. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 431.

Reviewed By

Review Date: 09/16/2011

Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Parinaud oculoglandular syndrome?

Definition

Parinaud oculoglandular syndrome is an eye problem similar to conjunctivitis ("pink eye"). It usually affects only one eye and is accompanied by nearby swollen lymph nodes and an illness with a fever.

Alternative Names

Oculoglandular syndrome

Causes, incidence, and risk factors

Parinaud oculoglandular syndrome (POS) is caused by an infection by bacteria, virus, fungus, or a parasite.

The most common causes are cat-scratch disease and tularemia (rabbit fever). The bacteria that cause either condition can infect the eye. Either the bacteria can directly enter the eye (on a finger or other object), or air droplets that carry the bacteria can land on the eye.

Other infectious diseases may spread this same way, or through the bloodstream to the eye.

Symptoms
  • Red, irritated, and painful eye (looks like "pink eye")
  • Fever
  • General ill-feeling
  • Increased tearing (possible)
  • Swelling of nearby lymph glands (often in front of the ear)
Signs and tests

An examination shows:

  • Fever and other signs of illness
  • Red, tender, inflamed eye
  • Tender lymph nodes may be present in front of the ear
  • There may be growths (conjunctival nodules) on the inside of the eylid or the white of the eye

Blood tests will be done to check for infection. A white blood cell count may be high or low, depending on the cause of the infection.

Blood tests to check antibody levels is the main method used to diagnose many of the infections that cause POS. Other tests may include:

Treatment

Depending on the cause of the infection, antibiotics may be helpful. Surgery may be necessary in rare cases to clean away the infected tissues.

Expectations (prognosis)

The outlook depends on the cause of the infection. In general, if the diagnosis is made early and treatment starts immediately, the outcome of POS can be very good.

Complications

Serious complications are rare.

The conjunctival nodules can sometimes form sores (ulcers) during the healing process. The infection can spread to nearby tissues or into the bloodstream.

Calling your health care provider

You should call your health care provider if you develop a red, irritated, painful eye.

Prevention

Frequent hand washing can reduce the likelihood of getting POS. Avoid being scratched by a cat, even a healthy cat. You can avoid tularemia by not having contact with wild rabbits, squirrels, or ticks.

References

Tu EY. Parinaud's oculoglandular syndrome. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 4.

Reviewed By

Review Date: 07/28/2010

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Where can I find information on corrective eye surgery?

You can find information on corrective eye surgery from you eye doctor. He or she sees hundreds of patients each year who come in to have exams to acquire corrective eye ware. Your optometry office usually keep a list of Ophthalmologist on hand in the event there needs to be further evaluation of the eye for reasons other than vision. When you visit the ophthalmologist you can talk to him or her about corrective eye surgery.

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Ophthalmologists

Ophthalmologists Review?

Choosing a good ophthalmologist in your local community is sometimes difficult if you do not know where to find local reviews. If you need eye care, there are resources available to help you find the right ophthalmologist for treatment.

The Better Business Bureau

You local Better Business Bureau provides a list of all registered businesses in your area, along with a comprehensive discussion of any complaints about those businesses, and the resolution of those complaints. While your local Better Business Bureau does not offer reviews of local ophthalmologists, examining the complaints and resolutions helps you differentiate between the good and bad specialists in your community.

Yelp.com

One very valuable website for finding local reviews for ophthalmologists, as well as any other types of business, is yelp.com. Yelp is accessible to anyone surfing the internet, and provides comments, reviews and ratings for local businesses that are posted by local residents. These comments are sorted by location, office and date, making the reviews both consistent and current.

Sites like yelp.com require constant user input to maintain information that is both current and relevant to consumer needs. If you routinely visit local businesses, leaving reviews of your own helps other consumers make informed choices. Local websites in metropolitan areas

Many websites are tailored to finding specific business information in a local metropolitan area, and include reviews of business located in that community. Use Google, or your search engine of choice, to find reviews for ophthalmologists in your city. If your metropolitan area has consumer-review websites, finding the reviews you need only requires a click of a mouse.

While finding reviews of local ophthalmologists is often difficult, the Better Business Bureau and consumer-driven sites like yelp.com provide resources for determining the quality of local wellness providers. With a little effort, it is possible to choose an ophthalmologist with confidence.

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Ophthalmologists

What Is A Routine Eye Exam?

Having a routine eye examination is important for all people to maintain healthy vision. Children need early eye exams to ensure that they can see well enough to excel in school, and adults need them to make sure they can see properly to drive and to correct problems that arise as they age. However, many people get nervous when they have to go to the doctor. Get the information on what your eye doctor screens you for so that you can have a comfortable, educated experience during your next eye exam.

What is an eye exam?

An eye exam is a text that a ophthalmologist or optometrist gives to check a person's eyes. These examinations include a number of different tests, each specialized and for a specific purpose. These tests can take a half hour or more to administer. Some of the tests gauge vision or visual responses, and others check for eye health or problems.

Both types of eye doctors are licensed to give eye examinations. However, an optometrist may refer you to an ophthalmologist because ophthalmologists often have certain areas of specialization. Visual acuity tests

One part of the eye examination usually involves a visual acuity test. This visual acuity test usually consists of the patient looking at a standard eye chart and reciting the letters off the chart to the examiner. The test is used to measure how well a person sees far away and up close.

Cover test

Another test that an optometrist or ophthalmologist may give as part of an examination is a cover test. The cover test is used to see how well both of your eyes work together. During the test, the eye doctor has the patient look at a target object, covers each eye and then looks for signs of strain. This test can help identify if the patient has a 'lazy eye' or any other eye alignment issues.

Refraction

During a refraction test, the eye doctor puts a large eye piece in front of the patient's face that has many lenses. This instrument is called a phoropter. Using the phoropter, the doctor switches from lens to lens and asks the patient if the lens is clearer or blurrier than the lens before it. This helps the eye doctor to pinpoint exactly what prescription to give someone who needs glasses or contacts, or helps to identify what the sight of the person is. Normal or optimal eyesight is 20/20 vision.

Getting an annual eye examination is an important part of maintaining optimal vision and eye function. Also, it is nothing to get really worried about, because now you have a better understanding of what goes on during an eye exam.

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Ophthalmologists

Maintaining Eye Health and Vision: Important Considerations for Seniors?

Vision changes are a normal part of growing older. It may become difficult to read fine print, judge distances, discern colors and adjust to changes in lighting. Over time, seniors may experience some of the following conditions that can affect eyesight:

  • Presbyopia, or difficulty focusing on close objects
  • Clouding of the eye's lens
  • Spots that float across the field of vision
  • Dry or watery eyes

Common diseases that can lead to vision loss include glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy. Glaucoma is an eye disorder in which the optic nerve is impaired, permanently impacting vision. People with AMD may experience a decline in central vision and the ability to see small detail, while patients with diabetic retinopathy have retinal damage that occurs as a result of diabetes mellitus.

It is important to take the following steps to preserve eyesight, especially after the age of 50, since older adults have an elevated risk of eye disease and vision problems:

  • Schedule regular examinations by a vision specialist (ophthalmologist) to help identify eye disease early and reduce the likelihood of future vision loss.
  • Increase lighting around the house to reduce eye strain.
  • Avoid smoking. Studies have shown that smoking can increase the risk of AMD.
  • Keep eyes protected when cooking, spraying aerosolized materials or using chemicals.
  • Increase consumption of vitamins and minerals associated with eye health. Food like melons, citrus, carrots, spinach and kale may help slow the progression of age-related eye diseases.

Seniors should seek prompt medical attention if they notice recent changes in visual acuity. A doctor's visit should be scheduled if any of the following issues are occurring:

  • Frequent squinting or increased sensitivity to light
  • Recurrent spills, misjudgment of an object's location, or falls
  • Difficulty reading
  • Presence of flashes or rapid movement in the peripheral vision
  • Inability to identify objects when driving at night or frequent driving mistakes
  • Uncontrolled eye movement

In many cases, vision loss can be corrected with glasses, medication or surgery. Seniors must be vigilant, however, about maintaining regular appointments with an ophthalmologist and monitoring themselves for any vision changes.

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Ophthalmologists

Vision and Eye Doctor Money Saving Tips?

We all need proper eye care at some point in our lives. But like other health care expenses, seeing the optician and optometrist can be costly. There are some tips you can use that can save you money when you have vision problems or need a new pair of eyeglasses.

Chain Stores

These are usually discount, franchise, eye care shops that can offer much lower priced eye care services than those from a doctor in private practice. They can make this possible because they serve and help so many customers across the nation. This makes their supplies cost less.

They can then pass this savings onto you the consumer. At these shops, you can often buy two pairs of eyeglasses for less than $100, including the frames and lenses. The eye examinations are also very inexpensive. This should be the very first stop when you want or need to save money on your eye care.

Vision Insurance

If your employer offers you health insurance, such as major medical and a prescription drug plan, you can often also obtain dental and vision coverage. You'll need to ask about it and fill out several more health forms. But by paying a little bit more into the plan every week or every month, you'll be able to be covered for both eye exams and prescription glasses at most any optician or optometrist that you choose.

Some plans will also allow you to see a medical eye specialist, such as an ophthalmologist, if you suspect you may have more serious vision problems. And if your company doesn't offer this plan, you could always try to round up enough workers around the office who would be interested. Then when enough are willing to pay into it and sign up, your company just might want to implement vision coverage into the overall health care plan.

If you're self employed, you can also obtain vision insurance by adding it to your current major medical insurance plan. You'll discover that the extra premium amounts will be very low in comparison to the overall cost savings of eye exams and new eyeglasses. Often, all you'll pay is a $3-$10 copay for office visits and each pair of glasses, instead of hundreds.

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Ophthalmologists

Fuchs' dystrophy?

Definition

Fuchs' (pronounced Fooks) dystrophy is an eye disease in which cells lining the inner surface of the cornea slowly start to die off. The disease usually affects both eyes.

Alternative Names

Fuchs' endothelial dystrophy, Fuchs' corneal dystrophy

Causes, incidence, and risk factors

Fuchs' dystrophy can be inherited, which means it can be passed down from parents to children. In some families, it is inherited in an autosomal dominant manner. That means that if either of your parents has the disease, you have a 50% chance of developing the condition.

However, the condition may also occur in persons without a known family history of the disease.

Fuchs' dystrophy is more common in women than in men. Vision problems usually do not appear before age 50, although doctors may be able to see signs of the disease in affected persons at an earlier age, usually in their 30s and 40s.

Fuchs' dystrophy affects the thin layer of cells that line the back part of the cornea. This layer is called the endothelium. The disease occurs when these cells slowly start to die off. (The cause is unknown.) The cells help pump excess fluid out of the cornea. As more and more cells are lost, fluid begins to build up in the cornea, causing swelling and a cloudy cornea.

At first, fluid may build up only during sleep, when the eye is closed. As the disease gets worse, small blisters may form in the endothelium. The blisters get bigger and may eventually break, causing eye pain. Fuchs' dystrophy can also cause the shape of the cornea to change, causing further vision problems.

SymptomsSigns and tests

A doctor can diagnose Fuchs' dystrophy during a slit-lamp examination.

Additional tests that may be done include:

  • Pachymetry -- measures the thickness of the cornea
  • Specular microscope examination -- allows the doctor to look at thin layer of cells that line the back part of the cornea
  • Visual acuity test
Treatment

Eye drops or ointments that draw fluid out of the cornea are used to relieve symptoms of Fuchs' dystrophy.

If painful sores develop on the cornea, soft contact lenses or surgery to create flaps over the sores may help reduce pain.

The only cure for Fuchs' dystrophy is a corneal transplant. Fuchs' dystrophy is one of the leading reasons for corneal transplantion in the United States.

Deep lamellar keratoplasty (DLK) is an alternative to a traditional transplant. In this procedure, only the deep layers of the cornea are replaced with donor tissue. The procedure requires no stitches. Recovery time is faster and there are fewer complications, such as rejection.

Expectations (prognosis)

Fuchs' dystrophy gets worse over time. Without a corneal transplant, a patient with severe Fuchs' dystrophy may become blind or have severe pain and very reduced vision.

Mild cases of Fuchs' dystrophy often worsen after cataract surgery. A cataract surgeon will evaluate this risk and may modify the technique or the timing of your cataract surgery.

Complications

Complications of Fuchs' dystrophy include:

  • Light sensitivity
  • Mild to severe vision loss
  • Frequent, severe pain as the disease gets worse
Calling your health care provider

Call your health care provider if you have:

  • Eye pain
  • Eye sensitivity to light
  • The feeling that something is in your eye when there is nothing there
  • Vision problems such as seeing halos or cloudy vision
  • Worsening vision
PreventionThere is no known prevention. Avoiding cataract surgery or taking special precautions during cataract surgery may help slow down the course of the disease. References

Cockerham GC, Kenyon KR. The corneal dystrophies. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 16.

Vanmeter WS, Lee WB, Katz DG. Corneal edema. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 16A.

Reviewed By

Review Date: 07/28/2010

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Visual field?

Definition

The visual field refers to the total area in which objects can be seen in the side (peripheral) vision while you focus your eyes on a central point.

Alternative Names

Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam

How the test is performed

Confrontation visual field exam: This is a quick and basic check of the visual field. The health care provider sits directly in front of you. You will cover one eye, and stare straight ahead with the other. You will be asked to tell when you can see the examiner's hand.

Tangent screen or Goldmann field exam: You will sit about 3 feet from a screen with a target in the center. You will be asked to stare at the center object and let the examiner know when you can see an object that moves into your side vision. This exam creates a map of your entire peripheral vision.

Automated perimetry: You sit in front of a concave dome and stare at an object in the middle. You press a button when you see small flashes of light in your peripheral vision. Your responses help determine if you have a defect in your visual field.

How to prepare for the test

No special preparation is necessary.

How the test will feel

There is no discomfort with this test.

Why the test is performed

This eye exam will show whether you have a loss of vision anywhere in your visual field. The pattern of vision loss will help your doctor diagnose the cause.

Normal Values

The peripheral vision is normal.

What abnormal results mean

Abnormal results may be due to diseases or central nervous systemdisorders, such as tumors that damage or press on (compress) the parts of the brain that deal with vision.

Other diseases that may affect the visual field of the eye include:

What the risks are

The test has no risks.

Special considerations

Your health care provider will discuss with you the type of visual field testing to be done.

References

Piltz-Seymour JR, Heath-Phillip O, Drance SM. Visual fields in glaucoma. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 49.

American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Budenz DL. Visual field testing in glaucoma. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO: Mosby Elsevier;2008:chap 10.5.

Reviewed By

Review Date: 02/10/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, Unviersity of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Slit-lamp exam?

Definition

The slit-lamp examination looks at structures that are at the front of the eye.

Alternative Names

Biomicroscopy

How the test is performed

The slit-lamp is a low-power microscope combined with a high-intensity light source that can be focused to shine in a thin beam.

You will sit in a chair with the instrument placed in front of you. You will be asked to rest your chin and forehead on a support to keep your head steady.

The health care provider will examine your eyes, especially the eyelids, cornea, conjunctiva, sclera, and iris. Often a yellow dye (fluorescein) is used to help examine the cornea and tear layer. The dye is either added as a drop, or the health care provider may touch a fine strip of paper stained with the dye to the white of your eye. The dye rinses out of the eye with tears as you blink.

Next, drops may be placed in your eyes to widen (dilate) your pupils. The drops take about 15 to 20 minutes to work. The slit-lamp examination is then repeated using another small lens held close to the eye, so the back of the eye can be examined.

How to prepare for the test

No special preparation is necessary for this test.

How the test will feel

Your eyes will be sensitive to light for a few hours after the exam if dilating drops are used.

Why the test is performed

This test is used to examine the:

Normal Values

Structures in the eye are found to be normal.

What abnormal results mean

The slit lamp exam may detect many diseases of the eye, including:

This list does not include all possible diseases of the eye.

What the risks are

The dilating drops may cause increased pressure in the eye with nausea and pain. This is very rare, but you should IMMEDIATELY return to your doctor's office if you experience either of these symptoms.

References

Fellman RL, Spaeth GL. Gonioscopy. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 44.

Colenbrander A. Principles of Ophthalmology. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 63.

American Academy of Ophthalmology Preferred Practice Patterns Committee: Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Miller D, Thall EH, Atebara NH. Ophtalmic instrumentation. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO: Mosby Elsevier;2008:chap 2.10.

Reviewed By

Review Date: 02/10/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Fluorescein angiography?

Definition

Fluorescein angiography is an eye test that uses a special dye and camera to look at blood flow in the retina and choroid, the two layers in the back of the eye.

Alternative Names

Retinal photography; Eye angiography

How the test is performed

Eye drops that make the pupil dilate will be given. You will be asked to place your chin on the camera's chin rest and your forehead against a support bar to keep your head still during the test.

The health care provider will take pictures of the inside of your eye. After the first group of pictures are taken, a dye called fluorescein is injected into a vein, usually at the bend of your elbow. Then, a special camera takes pictures as the dye moves through the blood vessels in the back of your eye.

How to prepare for the test

You will need someone to drive you home, because your vision may be blurred up to 12 hours after the test.

You may be told to discontinue drugs that could affect the test results. Tell your health care provide about any allergies, particularly reactions to iodine.

You must sign an informed consent form. You must remove contact lenses before the test.

Tell the health care provider if you may be pregnant.

How the test will feel

When the needle is inserted, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

When the dye is injected, you may have mild nausea and a warm sensation. These symptoms are usually very brief.

The dye will cause your urine to be darker, and possibly orange in color, for a day or two after the test.

Why the test is performed

This test is done to see if there is proper blood flow in the blood vessels in the two layers in the back of your eye (the retina and choroid).

It can also be used to diagnose problems in the eye or to determine how well certain eye treatments are working.

Normal Values

A normal result means the vessels appear a normal size, there are no new abnormal vessels, and there are no blockages or leakages.

What abnormal results mean

If blockage or leakage is present, the pictures will map the location for possible treatment.

An abnormal value on a fluorescein angiography may be due to:

  • Blood flow (circulatory) problems, such as blockage of the arteries
  • Cancer
  • Diabetic or other retinopathy
  • High blood pressure
  • Inflammation or edema
  • Macular degeneration
  • Microaneurysms -- enlargement of capillaries in the retina
  • Tumors
  • Swelling of the optic disc

Additional conditions under which the test may be performed:

What the risks are

There is a slight chance of infection any time the skin is broken. Rarely, a person is hypersensitive to the dye and may experience:

  • Dizziness or faintness
  • Dry mouth or increased salivation
  • Hives
  • Increased heart rate
  • Metallic taste in mouth
  • Nausea and vomiting
  • Sneezing

Serious allergic reactions are rare.

Your urine will be darker, and possibly orange in color, for a day or two after the test.

Special considerations

The test results are harder to interpret in people with cataracts.

References

Maguire JI, Federman JL. Intravenous fluorescein angiography. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 44.

Ciardella AP, Kaufman SR, Yannuzzi LA. The use of fluorescein angiography in acquired macular diseases. In: Tasman W, Jaeger EA, eds. Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 113F.

Reviewed By

Review Date: 07/28/2010

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Refraction test?

Definition

The refraction test is an eye exam that measures a person's prescription for eyeglasses or contact lenses.

Alternative Names

Eye test - refraction; Vision test - refraction; Refraction

How the test is performed

This test is performed by an ophthalmologist or optometrist. Both of these professionals are often called "eye doctor."

You sit in a chair that has a special device (called a phoroptor or refractor) attached to it. You look through the device and focus on an eye chart 20 feet away. The device contains lenses of different strengths that can be moved into your view. The test is performed one eye at a time.

The eye doctor performing the test will ask if the chart appears more or less clear when different lenses are in place.

How to prepare for the test

If you wear contact lenses, ask the doctor if you need to remove them before the test and for how long.

How the test will feel

There is no discomfort.

Why the test is performed

This test can be done as part of a routine eye exam. The purpose is to determine whether you have a refractive error (a need for glasses or contact lenses).

For people over age 40 who have normal distance vision but difficulty with near vision, a refraction test can determine the right power of reading glasses.

Normal Values

If your uncorrected vision (without glasses or contact lenses) is normal, then the refractive error is zero (plano) and your vision should be 20/20.

A value of 20/20 is perfect vision, meaning you are able to read 3/8-inch letters at 20 feet. A small type size is also used to determine normal near vision.

What abnormal results mean

You have a refractive error if you need a combination of lenses to see 20/20. Glasses or contact lenses should give you good vision.

If your final vision is less than 20/20, even with lenses, then there is probably another, non-optical problem with your eye.

The vision level you achieve during the refraction test is called the best-corrected visual acuity (BCVA).

Abnormal results may be due to:

Other conditions under which the test may be performed:

What the risks are

There are no risks.

Special considerations

You should have a complete eye examination every 3 - 5 years if you have no problems. If your vision becomes blurry, worsens, or if there are other noticeable changes, schedule an eye examination immediately.

After age 40 (or for people with a family history of glaucoma), eye examinations should be scheduled at least once a year to test for glaucoma. Anyone with diabetes should also have an eye exam at least once a year.

People with a refractive error should have an eye examination every 1 -2 years, or whenever their vision changes.

References

Katz M, Kruger PB. The human eye as an optical system. In: Tasman W, Jaeger Ea, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 33.

Kaufman JH. Subjective refraction: fogging and use of the astigmatic dials. In: Tasman W, Jaeger Ea, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 39.

Scott CA. Testing of refraction. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO: Mosby Elsevier;2008:chap 2.8.

Olitsky SE, Hug D, Smith LP. Examination of the eye. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 618.

American Academy of Ophthalmology Refractive Management/Intervention Panel. Preferred Practice Pattern Guidelines. Refractive Errors & Refractive Surgery. San Francisco, CA. American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Reviewed By

Review Date: 02/10/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Eye and orbit ultrasound?

Definition

An eye and orbit ultrasound is a test to look at the eye area, and to measure the size and structures of the eye.

Alternative Names

Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography

How the test is performed

The test is usually done in the ophthalmologist's office or the ophthalmology department of a hospital or clinic.

Your eye is numbed with medicine (anesthetic drops). The ultrasound wand (transducer) is placed against the front surface of the eye.

The ultrasound uses high-frequency sound waves that travel through the eye. Reflections (echoes) of the sound waves form a picture of the structure of the eye. The test takes about 15 minutes.

There are two types of scans -- A-scan and B-scan.

For the A-scan:

  • You will usually sit in a chair and place your chin on a chin rest. You will look straight ahead.
  • A small probe with some oil on it is placed against the front of your eye.
  • The test may also be done with you lying back. With this method, a fluid-filled cup is placed against your eye to do the test.

For the B-scan:

  • You will be seated and you may be asked to look in many directions. The test is usually done with your eyes closed.
  • A gel is placed on the skin of your eyelids. The B-scan probe is gently placed against your eyelids to do the test.
How to prepare for the test

No special preparation is needed for this test.

How the test will feel

Your eye is numbed, so you shouldn't have any discomfort. You may be asked to look in different directions to improve the ultrasound image or so it can view different areas of your eye.

A lubricant placed on the ultrasound wand may run on your cheek, but you won't feel any discomfort or pain.

Why the test is performed

Your doctor may order this test if you have cataracts or other eye problems.

An A-scan ultrasound measures the eye to determine the right power of a lens implant before cataract surgery.

A B-scan is done to look at the inside part of the eye or the space behind the eye that can't be seen directly. This may occur when you have cataracts or other conditions that make it hard for the doctor to see into the back of your eye. The test may help diagnose retinal detachment, tumors, or other disorders.

Normal Values

For an A-scan, measurements of the eye are in the normal range.

For a B-scan, the structures of the eye and orbit appear normal.

What abnormal results mean

A B-scan may show:

  • Bleeding into the clear gel (vitreous) that fills the back of the eye (vitreous hemorrhage)
  • Cancer of the retina (retinoblastoma), under the retina, or in other parts of the eye (such asmelanoma)
  • Damaged tissue or injuries in the bony socket that surrounds and protects the eye (orbit)
  • Foreign bodies
  • Pulling away of the retina from the back of the eye (retinal detachment)
  • Swelling (inflammation)
What the risks are

To avoid scratching the cornea, do not rub the numbed eye until the anesthetic wears off (about 15 minutes). There are no other risks.

References

Fisher YL, Nogueira F, Salles D. Diagnostic ophthalmic ultrasonography. In: Tasman W, Jaeger EA, eds. Duane's Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 108.

Coleman DJ, Silverman RH, Rondeau MJ, Daly SW, Lloyd HO. Evaluation of the posterior chamber, vitreous and retina with ultrasound. In: Tasman W, Jaeger EA, eds. Duane's al Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 3.

Massoud TF, Cross JJ. The orbit. In: Adam A, Dixon AK, Grainger RG, Allison DJ, eds. Grainger & Allison's Diagnostic Radiology. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 61.

Fisher YL, Klancnik Jr JM, Rodriguez-Coleman H, et al. Contact B-scan ultrasonography. In: Yanoff M, Duker JS, eds. Yanoff & Duker: Ophthalmology. 3rd ed. Philadelphia, Pa: Mosby Elsevier; 2008:chap 6.7.

Reviewed By

Review Date: 03/30/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Home vision tests?

Definition

Home vision tests measure the ability to see fine detail.

Alternative Names

Visual acuity test - home; Amsler grid test

How the test is performed

There are three vision tests that can be done at home: Amsler grid, distance vision, and near vision testing.

AMSLER GRID TEST:

This test helps detect macular degeneration, a disease that may cause blurred vision, distortion, or blank spots. If you normally wear glasses for reading, wear them for this test. If you wear bifocals, look through the bottom reading portion.

Do the test with each eye separately, first the right and then the left. Hold the test grid right in front of you, 14 inches away from your eye. Look at the dot in the center of the grid, not at the grid pattern.

While looking at the dot, you will see the rest of the grid in your peripheral vision. All the lines, both vertical and horizontal, should appear straight and unbroken. They should meet at all the crossing points with no missing areas. If any lines appear distorted or broken, note their location on the grid.

DISTANCE VISION:

This is the standard eye chart doctors use, which has been adapted for home use.

The chart is attached to a wall at eye level. Stand 10 feet away from the chart. If you wear glasses or contact lenses for distance vision, wear them for the test.

Check each eye separately, first the right and then the left. Keep both eyes open and cover one eye with the palm of the hand.

Read the chart, beginning with the top line and moving down the lines until it is too difficult read the letters. Record the number of the smallest line that you read correctly. Repeat with the other eye.

NEAR VISION:

This is similar to the distance vision test above, but it is held only 14 inches away. If you wear glasses for reading, wear them for the test.

Hold the near vision test card about 14 inches from your eyes. Do not bring the card any closer. Read the chart using each eye separately as described above. Record the size of the smallest line you were able to accurately read.

How to prepare for the test

You need a well-lit area at least 10 feet long for the distance vision test, and the following:

  • Measuring tape or a yardstick
  • Eye charts
  • Tape or tacks to hang the eye charts on the wall
  • A pencil to record results
  • Another person to help (if possible)

The vision chart needs to be tacked to the wall at eye level. Mark the floor with a piece of tape exactly 10 feet from the chart on the wall.

How the test will feel

The tests cause no discomfort.

Why the test is performed

Your vision may change gradually. You can adjust to the change without being aware of it.

Home vision tests can help detect eye and vision problems early. Perform home vision tests every year.

People who are at risk for macular degeneration may be told by their ophthalmologist to perform the Amsler grid test more often. It is best to do this test once a week. Macular degeneration changes are gradual, and you can miss them if you test daily.

Normal Values
  • Amsler grid test: All lines appear straight and unbroken with no distorted or missing areas
  • Distance vision test: All letters on the 20/20 line read correctly
  • Near vision test: You are able to read the line labeled 20/20 or J-1
What abnormal results mean

Abnormal results may mean you have a vision problem or eye disease and you should have a professional eye examination.

  • Amsler grid test: If the grid appears distorted or broken, there may be a problem with the retina.
  • Distance vision test: If you do not read the 20/20 line correctly, it may be a sign of nearsightedness (myopia), farsightedness(hyperopia), astigmatism, or another eye abnormality.
  • Near vision test: Not being able to read the small type may be a sign of aging vision (presbyopia).
What the risks are

The tests have no risks.

Special considerations

If you have any of the following symptoms, get a professional eye examination:

  • Difficulty focusing on near objects
  • Double vision
  • Eye pain
  • Feeling like there is a "skin" or "film" over the eye or eyes
  • Frequent changing of glasses
  • Light flashes, dark spots, or ghost-like images
  • Objects or faces looking blurred or foggy
  • Rainbow-colored rings around lights
  • Straight lines look wavy
  • Trouble seeing at night, trouble adjusting to darkened rooms

If children have any of the following symptoms, they should also have a professional eye examination:

  • Crossed eyes
  • Difficulty in school
  • Excessive blinking
  • Getting very close to an object (for example, the television) in order to see it
  • Head tilting
  • Squinting
  • Watery eyes
References

Colenbrander A. Measuring vision and vision loss. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 51.

Skarf B, Glaser JS, Trick GL. Neuro-ophthalmologic examination: the visual sensory system. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 2.

American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Miller D, Schor P, Magnante P. Optics of the normal eye. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier;2008:chap 2.6.

Reviewed By

Review Date: 02/10/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Visual acuity test?

Definition

The visual acuity test is used to determine the smallest letters a person can read on a standardized chart (Snellen chart) or a card held 14 - 20 feet away.

Alternative Names

Eye test - acuity; Vision test - acuity; Snellen test

How the test is performed

This test may be done in a health care provider's office, a school, a workplace, or elsewhere.

You will be asked to remove your glasses or contact lenses and stand or sit 20 feet from the eye chart. You will keep both eyes open.

Gently cover one eye with the palm of your hand, a piece of paper, or a paper cup while you read out loud the smallest line of letters you can see on the chart. Numbers or pictures are used for people who cannot read, especially children.

If you are not sure of the letter, you may guess. This test is done on each eye, one at a time. If needed, it is repeated while you wear your glasses or contacts. You may also be asked to read letters or numbers from a card held 14 inches from your face. This will test your near vision.

How to prepare for the test

No special preparation is necessary for this test.

How the test will feel

There is no discomfort.

Why the test is performed

The visual acuity test is a routine part of an eye examination or general physical examination, particularly if there is a change in vision or a problem with vision.

In children, the test is performed to screen for vision problems. Vision problems in young children can often be corrected or improved. Undetected or untreated problems may lead to permanent vision damage.

There are other ways to check vision in very young children, or in people who do not know their letters or numbers.

Normal Values

Visual acuity is expressed as a fraction.

  • The top number refers to the distance you stand from the chart. This is usually 20 feet.
  • The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read.

For example, 20/20 is considered normal. 20/40 indicates that the line you correctly read at 20 feet away can be read by a person with normal vision from 40 feet away.

Even if you miss one or two letters on the smallest line you can read, you are still considered to have vision equal to that line.

What abnormal results mean

Abnormal results may be a sign that you need glasses or contacts, or it may mean that you have an eye condition that needs further evaluation by a health care provider.

Related topics:

What the risks are

There are no risks.

References

Colenbrander A. Measuring vision and vision loss. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 51.

Miller D, Schor P, Magnante P. Optics of the normal eye. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO: Mosby Elsevier;2008:chap 2.6.

American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Reviewed By

Review Date: 02/10/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Electroretinography?

Definition

Electroretinography is a test to measure the electrical response of the eye's light-sensitive cells, called rods and cones. These cells are part of the retina (the back part of the eye).

Alternative Names

ERG; Electrophysiologic testing

How the test is performed

While you are in a sitting position, the health care provider places numbing drops into your eyes, so you will not have any discomfort during the test. Your eyes are held open with a small device called a retractor. An electrical sensor (electrode) is placed on each eye.

The electrode measures the electrical activity of the retina in response to light. A light flashes, and the electrical response travels from the electrode to a TV-like screen, where it can be viewed and recorded. The normal response pattern has waves called A and B.

The doctor will take the readings in normal room light and then again in the dark, after allowing 20 minutes for your eyes to adjust.

How to prepare for the test

No special preparation is necessary for this test.

How the test will feel

The probes that rest on your eye may feel a little scratchy. The test takes about 1 hour to perform.

Why the test is performed

This test is done to detect disorders of the retina. It is also useful in determining if retinal surgery is recommended.

Normal Values

Normal test results will show a normal A and B pattern in response to each flash.

What abnormal results mean

The following conditions may cause abnormal results:

What the risks are

The cornea may get a temporary scratch on the surface from the electrode. Otherwise, there are no risks with this procedure.

Special considerations

You should not rub your eyes for an hour after the test, as this could injure the cornea. Your doctor will discuss with you the results of the test and what it means for you.

References

Odom JV, Leys M, Weinstein GW. Clinical visual electrophysiology. In: Tasman W, Jaeger EA, eds. Duane's Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins;2009:chap 5.

Cleary TS, Reichel E. Electrophysiology. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. Maryland Heights, Mo: Mosby Elsevier;2008:chap 6.9.

Reviewed By

Review Date: 08/12/2010

David C. Dugdale, III, MD, Professor of Medicine, Division of Medicine, Department of Medicine, University of Washington School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

001
Ophthalmologists

Color vision test?

Definition

A color vision test checks your ability to distinguish between different colors.

Alternative Names

Eye test - color; Vision test - color; Ishihara color vision test

How the test is performed

You will sit in a comfortable position in regular lighting, and your health care provider will explain the test to you. You will be shown several cards with multicolored dot patterns. In the patterns, some of the dots will apear to form numbers or symbols.

You will be asked to identify the symbols, if possible.

As you cover one eye, the tester will hold the test plates 14 inches from your face and ask you to quickly identify the symbol found in each color pattern.

Depending on the problem suspected, you may be asked to determine the intensity of a color, especially in one eye compared to the other. This is often tested by using the cap of a red eyedrop bottle.

How to prepare for the test

If your child is having this test performed, it may be helpful to explain how the test will feel, and to practice or demonstrate on a doll. Your child will feel less anxious about the test if you explain what will happen and why.

Usually there is a sample card of multicolored dots that almost everyone can identify, even people with color vision problems.

If you or your child normally wears glasses, wear them during the test.

Small children may be asked to tell the difference between a red bottle cap and caps of a different color.

How the test will feel

The test is similar to a vision test.

Why the test is performed

This test is done to determine whether you have any problems with your color vision.

Color vision problems usually fall into two categories:

  • Present from birth (congenital) problems in the light-sensitive cells (cones) of the retina (the light-sensitive layer at the back of the eye)
  • Diseases of the optic nerve (the nerve that carries visual information from the eye to the brain)
Normal Values

Normally, you will be able to distinguish all colors.

What abnormal results mean

This test can determine the following color vision problems:

  • Achromatopsia -- complete color blindness, seeing only shades of gray
  • Deuteranopia -- difficulty telling the difference between red/purple and green/purple
  • Protanopia -- difficulty telling the difference between blue/green and red/green
  • Tritanopia -- difficulty telling the difference between yellow/green and blue/green

Problems in the optic nerve can show up as a loss of color intensity, although the test may be normal.

What the risks are

There are no risks associated with this test.

References

Adams AJ, Verdon WA, Spivey BE. Color vision. In: Tasman W, Jaeger EA, eds. Duane's Foundations of Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 19.

American Academy of Ophthalmology Preferred Practice Patterns Committee. Preferred Practice Pattern Guidelines. Comprehensive Adult Medical Eye Evaluation. San Francisco, CA: American Academy of Ophthalmology, 2010. Accessed January 17, 2011.

Olitsky SE, Hug D, Smith LP. Examination of the eye. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 618.

Reviewed By

Review Date: 02/10/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Photophobia?

Definition

Photophobia is eye discomfort in bright light.

Alternative Names

Light sensitivity; Vision - light sensitive; Eyes - sensitivity to light

Considerations

Photophobia is a fairly common symptom. For many people, photophobia is not due to any disease. Severe photophobia may occur with eye problems and can cause severe eye pain even in relatively low light.

Common Causes
  • Acute iritis or uveitis(inflammation inside eye)
  • Burns to the eye
  • Corneal abrasion
  • Corneal ulcer
  • Drugs such as amphetamines, atropine, cocaine, cyclopentolate, idoxuridine, phenylephrine, scopolamine, trifluridine, tropicamide, and vidarabine
  • Excessive wearing of contact lenses, or wearing badly fitted contact lenses
  • Eye disease, injury, or infection (such as chalazion, episcleritis, glaucoma)
  • Eye testing when the eyes have been dilated
  • Meningitis
  • Migraine headache
Home Care

You can reduce the discomfort of light sensitivity by:

  • Avoiding sunlight
  • Closing your eyes
  • Wearing dark glasses
  • Darkening the room

If eye pain is severe, see your health care provider to determine the cause of light sensitivity. Proper treatment may cure the problem. Seek urgent medical attention if your pain is moderate to severe, even in low-light conditions.

Call your health care provider if

Call your doctor if light sensitivity is severe or painful -- for example, if you need to wear sunglasses indoors.

Also call if the sensitivity occurs with headaches, red eye or blurred vision or does not go away in a day or two.

What to expect at your health care provider's office

The doctor will perform a physical examination, including an eye exam. You may be asked the following questions:

  • When did the light sensitivity begin?
  • Does it hurt all the time or just sometimes?
  • How bad is it?
  • Do you need to wear dark glasses or stay in dark rooms?
  • Did a doctor recently dilate your pupils?
  • Have you used any eye drops?
  • Do you use contact lenses?
  • Have you used soaps, lotions, cosmetics, or other chemicals around your eyes?
  • Have you been around dust, wind, sun, pollen, or chemicals?
  • Does anything make the sensitivity better or worse?
  • Have you been injured?
  • What medicines do you take?
  • What other symptoms do you have?

Tell your doctor if you have any of these symptoms:

  • Pain in the eye
  • Headache
  • Nausea
  • Neck stiffness
  • Blurred vision
  • Sore or wound in eye
  • Redness
  • Itching
  • Swelling
  • Dizziness
  • Numbness or tingling elsewhere in the body
  • Changes in hearing

The following tests may be done:

References

Godfrey WA. Acute anterior uveitis. In: Tasman W, Jaeger EA, eds. Duane's Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 40.

Troost BT. Migraine and other headaches. In: Tasman W, Jaeger EA, eds. Duane's Clinical Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 16.

Steinemann TL, Ehlers W, Suchecki J. Contact lens-related complications. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier; 2008:chap 4.24.

Sharma R, Brunette DD. Ophthalmology. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2009:chap 69.

Reviewed By

Review Date: 06/01/2011

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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Ophthalmologists

Vision - night blindness?

Definition

Night blindness is poor vision at night or in dim light.

Alternative Names

Nyctanopia; Nyctalopia; Night blindness

Considerations

Night blindness may cause problems with driving at night. People with night blindness often have trouble seeing stars on a clear night or walking through a dark room, such as a movie theater.

These problems are often worse just after a person is in a brightly lit environment. Milder cases may just have a harder time adapting to darkness.

Common Causes

The causes of night blindness fall into two categories: treatable and nontreatable.

Treatable causes:

Nontreatable causes:

Home Care

Take safety measures to prevent accidents in areas of low light. Avoid driving a car at night, unless you get your eye doctor's approval.

Vitamin A supplements may be helpful if you have a vitamin A deficiency. Ask your doctor.

Call your health care provider if

It is important to have a complete eye exam to determine the cause, which may be treatable. Call your eye doctor if symptoms of night blindness persist or significantly affect your life.

What to expect at your health care provider's office

Your health care provider will examine you and your eyes. The goal of the medical exam is to determine if the problem can be corrected (for example, with new glasses or cataract removal), or if the problem is due to something more serious.

The doctor may ask you questions, including:

  • When did the night blindness begin?
  • Did it occur suddenly or gradually?
  • Does it happen all the time or just sometimes?
  • How severe is the night blindness?
  • Are you nearsighted?
  • Do you have other vision changes?
  • What other symptoms do you have?
  • Do you have unusual stress, anxiety, or a fear of the dark?
  • Does using corrective lenses improve night vision?
  • What medications do you use?
  • How is your diet?
  • Have you recently injured your eyes or head?
  • Do you have a family history of diabetes?

The eye exam will include:

Other tests may be done:

References

Tomsak RL. Vision loss. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann;2008:chap 14.

Sieving PA, Caruso RC. Retinitis pigmentosa and related disorders. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO;Mosby Elsevier;2008:chap 6.10.

Reviewed By

Review Date: 07/28/2010

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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