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Convex lenses are thicker in the middle then the edges and concave are thicker at the edges then the middle. When light travels through lenses, refraction occurs. The light bends either outward or inward, it depends on the lens.
The lens of your eye is a double convex lens. Its job is to focus the image on the retina of the eye. If one is farsighted, the lens in the eye causes the focus to be behind the retina. These people see far but have some difficultly seeing close-up.
To correct this farsightedness, the person would wear glasses or contacts with convex lenses, for It is often used for close examination of small objects.
Wiki User
∙ 13y ago
Wiki User
∙ 13y agoLong sightedness is corrected by wearing spectacles having convex lens of such a focal length which forms a virtual image of the object. Hence a clear image of the object is formed on retina.
Short sightedness can be corrected by wearing spectacle having suitable concave lens. This concave lens helps the light, coming from the object, to diverge.
Wiki User
∙ 12y agoFarsightedness can usually be corrected using convex lenses.
Wiki User
∙ 13y agoThe lenses needed if you are nearsighted are Concave Lenses
Wiki User
∙ 13y agoConcave lenses are used to correct nearsightedness.
Wiki User
∙ 11y agoa concave lens
Wiki User
∙ 13y agoconcave and diverging
Wiki User
∙ 11y agoa converging lens or concave
Wiki User
∙ 11y ago-2.75
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Why are concave lens used in spectacles?
Because they alter the focus of the lens in the patients eye, to correct their vision.
How does a concave lens correct nearsightedness?
The eye lens may become too thick & its focal length is reduced. the ciliary muscles are not able to relax sufficiently to make the eye lens thin when viewing distant objects. So, they are unable to increase the focal length of the lens & the image is formed before retina. Since short sightedness occurs due to excessive convergence of light rays by the eye lens, it can be corrected by using a diverging lens, i.e, a concave lens. A properly chosen focal length of a concave lens compensates the extra convergence of the eye lens thus, removing the defect. The scientific name of short sightedness is myopia.
What type of lens are used to correct vision problems?
It depends on what the vision 'problem' is. Convex lenses are used to correct short-sighted errors, while concave lenses correct long-sighted problems.
What type of lens is needed to correct hypermetropia?
Converging lenses....or....convex lens.
Which lens is used in a magnifying glass?
it is used in a concave lens
What is the common way to correct nearsightedness?
Place a concave lens in front of th eeye
What ocular lens is used for near sight?
The ocular lens used for nearsightedness is known as a diverging lens. It is also known as a concave lens.
What is a visual problem where the lens focuses just behind the retina?
Farsightedness NOT nearsightedness
When the image of a distant object is brought into focus in front a a persons retina the defect is called?
The image of a distant object is brought into focus in front of a person's retina, the defect is called nearsightedness. A virtual image produced by a lens is always located in front of the lens.
What distance would an eye doctor need to measure to correct a problem with nearsightedness or farsightedness?
To correct nearsightedness surgoens remove tissue from the center of the cornea.
What is radial keratotomy?
Radial keratotomy (RK) is a type of eye surgery used to correct myopia (nearsightedness).
Lens used for shortsightedness?
One uses a divergent lens to correct for shortsightedness.
What is a sentence for concave lens?
A Concave lens is used to correct short- sightedness.
What is a sphere single visi eyeglass lens?
The sphere part means it is correcting for either farsightedness or nearsightedness. The single vision part means they correct for one distance weather it be reading, distance or intermediate range. It means it does not correct for astigmatism or bifocal accommodation.
Why are concave lens used in spectacles?
Because they alter the focus of the lens in the patients eye, to correct their vision.
What bi word means having two lenses on one glass?
The term "bifocal" refers to eyeglasses with two distinct optical powers, typically used to correct both nearsightedness and farsightedness in a single lens.
Which lenses should be used to correct the defect of astigmatism?
Cylindrical lens
