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We were studying about different kind of lenses. How can contact lenses help people see better, when they are on top of your eyes?
Question Date: 1997-11-14
Answer 1:

Well, they help you see clearer for the same reason a telescope works so well. Light rays become bent when they travel through glass...and the thicker the glass the more they get bent. So as light moves through a glass lens, the light entering the lens along the edge is bent LESS than the light going through the center. It is this differential bending of light that COMPENSATES for the mis-shape of the lens in your eye!!!! so the important point is that the contact lens or the glasses you wear are IN FRONT OF YOUR EYE. The closeness is not so important; the key is that the correction to the bending of the light rays is made BEFORE the light actually enters your eye.

Answer 2:

Your question implies that you know that some distance is needed for a lens to focus an image. It would seem then that since the contact lenses are touching the eye, then there is no distance for the focusing to occur.

You should think about how the eye is put together. The eye is a ball. On one side of the ball is the eye's lens; on the other is the retina, which are the nerves that detect light. In between, in the center of the ball, is clear fluid. Light going through theeye's lens is focused onto the retina creating a sharp image.

How will a contact lens help this if your lens doesn't work correctly?

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