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reflection and stuff

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Title: reflection and stuff Author: tom vining Last modified by: Tom Vining Created Date: 4/25/2005 4:44:12 PM Document presentation format: On-screen Show (4:3) – PowerPoint PPT presentation

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Title: reflection and stuff


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MyopiaMyopia is more commonly known as
nearsightedness. If the eye has myopia, the eye
is too long,  and the image falls short of the
retina when the target object is far away.
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  • Concave lenses are used to correct Myopia.  They
    spread the light out before it reaches the convex
    lens in the eye, therefore letting the image
    focus directly on the retina.

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HyperopiaPeople with hyperopia (farsightedness)
will usually see far-away objects, such as the
TV, crystal clear (unless the hyperopia is very
severe), but cannot see close objects clearly.
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  • Hyperopia can be corrected with a convex lens. A
    convex lens focuses the light in addition to the
    natural lens and makes the image focus exactly on
    the retina. Many people have hyperopia as a kid,
    but some of them lose is as the eyeball grows
    longer with normal growth.

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Astigmatism
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