What Causes Cataracts?
Protein fibers in the lens, called crystallines, are
precisely arranged in thousands of layers. Usually
because of aging, the proteins deteriorate or become
"disarranged." Some scientists believe that these
fragmented proteins cause the densities, or
"clumps," that cloud areas of the lens. These dense
areas are cataracts, and as they become larger they
cause noticeable vision loss.
People sometimes confuse cataracts with an
unrelated lens condition, presbyopia-a stiffening of
the lens also caused by aging. Throughout life, the
lens continues to manufacture new layers of cells,
and the accumulation of layers makes the lens less
pliable. As the lens loses its flexibility, it also loses
the ability to accommodate as well as it once could.
At about age forty-five, most people-even those
who have had excellent vision-find that "their arms
are too short." They have to hold books and
magazines farther from their eyes in order to focus
on the print. If presbyopia is your only vision
problem, you can probably solve it with inexpensive
reading glasses.
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