Nearsightedness
and Farsightedness
In nearsightedness, the image formed by the front of
the eye (including the lense) is located BEFORE the retina, where it should
be...
Farsighted people have their image located BEHIND the
retina.
The result of these problems is fuzzy vision... for nearsighted
people (myopic), they can see up close things but not far away, and farsighted
people (hyperopic) can see far things, but not up close ones.
How do you fix these problems?
To move the image of a nearsighted person back toward
the back of the eye, we must "spread out" the incoming light, so a concave
lense is used.
To move the image of a farsighted person up toward the
back of the eye, we must "bring together" the incoming light, so a convex
lense is used.
MORE TO COME SOON, I HOPE! (today
is 5/1/2000)