Cataract: An Overview
Though many people have heard of cataracts, not everyone knows exactly what they
are. Contrary to popular belief, they are not a film growing over your eye. A cataract
is actually a cloudiness that grows within the lens of the eye, preventing light
from passing to the retina. This can blur your vision, similar to looking out of
a foggy window.
To better understand how cataracts develop and affect your vision, it helps to know
how the eye works. Light enters the eye through the cornea, the clear layer covering
the front of the eye. The lens of the eye, behind the cornea, changes shape to focus
the light onto the retina at the back of the eye. Here, photoreceptors in the eye
send nerve signals through the optic nerve to the brain where the nerve impulses
are processed into sight.
Cataracts in your lenses form naturally as you age and can affect this process.
Dead cells shed from your eye’s lens and gather to form clouded spots. These old
cells become compacted into the center of the lens, resulting in a cataract. Sometimes
cataracts remain small and unnoticeable, but they often develop over time and prevent
light from focusing properly onto the retina. This is what sometimes causes blurred
vision.