Full Corrective Lenses Description [Continued from above] . . .
Nearsightedness, sometimes called myopia, is a condition in
which a person sees near objects more clearly than distant ones.
The near vision is not necessarily good; it is just better than
the far vision. A cornea that is too curved, an elongated
eyeball, or both cause this defect. This causes the light rays
from objects far away to be focused some distance in front of
the retina and, by the time the light has finished its journey,
it has started to spread out, giving a blurred spot of light
instead of a sharp image. Farsightedness, or hyperopia, is the
opposite of myopia, with distant vision being sharper than close
vision but, in this case, the cornea and lens do not bend the
light rays enough, so that they reach the retina before they
come into sharp focus-again, giving a blurred focus. Presbyopia
has similar effects to those of farsightedness, making near
objects appear blurred, but it is a separate condition, usually
caused by the gradual fa