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the lenses used for near sighted people are cancave lenses so that the image forms farther back on the retina and for far sighted people, a convex lens is used to make the image fall right on the retina!! =D XD
hope this helped!! :)
Wiki User
∙ 13y ago
Wiki User
∙ 9y agoA patient with nearsightedness will usually need minus lenses to see clearly in the distance. If you have just received an eye examination and seen your doctor quickly scribble a bunch of numbers onto a prescription pad, you may have been curious to know what type of lenses he or she prescribed and the reasoning behind it.
A person with nearsightedness has a eye condition known as myopia. A myopic prescription will have a minus sign in front of the first three digits on your prescription. An example would be -3.50. The higher the number after the minus sign the worse your vision will be at viewing objects at a distance. The units after the -3.50 are known as diopters which measure your refractive condition.Lenses are mostly common placed into a eyeglasses frame to wear when viewing objects at a distance. What you will notice about a minus lens is that the edges of the lens will be thicker than the center part of the lens. This is so that light can be refracted, or redirected, further back onto the retina. Myopic individuals have eyeballs that are too long for where light naturally falls onto the retina. Minus lenses help to focus light further back in order to reach the retina. Unfortunately, the higher the degree of myopia the increased risk for eye diseases such as macular degeneration and retinal detachments.
Eyeglasses are not the only method of treating myopia. Patients with myopia can also be treated with contact lenses, corneal reshaping, and refractive eye surgery. Contact lenses can be hard or soft lenses that have similar properties to glasses except that they are placed directly onto the eye. Patient will wear them during the day as needed and remove them before going to bed. Corneal reshaping involves a molding retainer that will flatten the cornea to correct for myopia. These retainers are worn only while asleep and are ideal for children who are getting more nearsighted as they age. Lastly, refractive surgery involves a laser that can reshape the curvature of the cornea to eliminate symptoms of myopia.
Wiki User
∙ 7y agoIt is easier to say that these people can see well close up. They are myopic because they see well close up and not very well far away. Concave lens are used to help correct the problem of not seeing well at a distance.
Wiki User
∙ 11y agoThe difference between those two glasses are nearsighted people cannot see object in distance but they can see stuff near them. People with farsighted is the opposite of it.
Wiki User
∙ 12y agoConcave lenses...
Wiki User
∙ 13y agoThey use convex lenses.
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When a person is far sided do the need a concave lens or convex lens?
Farsighted people use convex lenses to correct their vision.(This is the correct answer!)
If you need glasses are you near or far sighted if you can't see close up?
Near Sighted. If you need glasses if you cant see close up, you are far sighted. You need the glasses to see close up, so your not near sighted.
How can the word ''near-sighted'' be used in a sentence?
I need my glasses for driving because I am too near-sighted to read the traffic signs.
What kind of glasses do you need if you are near sighted?
you need big round ones like c boyce
What kind of lenses would a farsighted person need to correct their vision?
Hyperopic, plus powered, or convex lenses.
Can you have astigmatism in one eye?
No, you can only be either short or long sighted. An astigmatism means you need a cylinder in your glasses to see properly. You can be either far sighted or near sighted and also have an astigmatism.
Why are so many people near-sighted?
Near sightedness or Myopia is mainly caused by the eye being too long, rays of light focus in front of the retina.Far sightedness or Hyperopia is mainly caused by the eye being too short, rays of light focus behind the retina.Lots of children are born with Hyperopia but "grow out" of it because as they, grow, the eye lengthens.That is why more people are near sighted, you can't "grow out" of it.AnswerYour eyes have to be perfectly round to have perfect vision. the real question is why so many people don't need glasses?
What happens if the light is focused behind or in front of the retina?
You will need glasses. If its focused in front of your retina then you're near-sighted (can't see close up). If its focused behind your retina then you're far-sighted (can't see far away)
What is it called if you can not see objects up close clearly?
I don't really understand your question. However that means that you may need glasses. That is very normal and means that you're close sighted not far sighted like others which is okay. Just go to your eye doctor and they'll give you some prescription glasses. Thanks! =D
Will you need far or near glasses after Cataract Surgery?
Now when they remove the cloudy lenses in Cataract Surgery they replace them with plastic lenses focused for far vision, so you will need glasses for near vision. Many people get bifocals with no prescription for the main lens part and the near vision prescription for the bifocal part. Other people just carry prescription near vision glasses for when they need to look at things close up but normally wear no glasses at all.Years ago (before they began putting in plastic lenses) everyone needed glasses all the time after having Cataract Surgery, because there was no longer any lens in the eye to focus the light.
What type of lens are need if you are nearsighted?
Lenses can correct vision problems by bending light rays before they reach the eye, in effect moving the focal point of the eye's lens so that it falls upon the retina and creates a clear image. Concave lenses cause light rays to converge and lengthen the focal point for the near sighted eye. Concave lenses are thinner in the middle and thicker on the edges and may be curved on one or both sides. Concave lenses cause light rays to diverge, or spread apart. :)
What is purpose of eye refraction exam?
When you can not see the near or distant objects clearly, you need refraction examination of your eyes. You may be suffering from, what is called as astigmatism. In that case you may have headache. You need cylindrical lens in that case.
