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| Macular
degeneration is a general term that is used to describe a group of disorders
that affect the central portion of the retina known as the macula. The
retina is the tissue that lines the back inside wall of the eye. This tissue,
like the film on the inside of a camera, is the seeing tissue. The macula
represents a small central portion of the retina responsible for fine detail
vision. The large area of the retina surrounding the macula is called the
peripheral retina and is responsible for side vision or "vision around
the edges". The retina interconnects to the optic nerve through an intricate
series of hook-ups from nerve endings from the center and side of the retina.
Center vision is hooked up for 20/20 vision, color vision, and vision to
see well in the bright light. Side vision is hooked up not for detail but
for seeing shapes and movements, dark vs. light objects, night vision and
some color vision.
Macular Degeneration is a condition in
which there is a break down of the tissue in the center seeing area. It
is important to realize that even though the macula is important for vision
it represents only a small portion of the entire retina. If one imagines
the inside of the eye to be the size of an ordinary cereal bowl, the area
known as the macula would be only about the size of a quarter sitting in
the bottom of the bowl. Macular Degeneration rarely injures the retina
outside of this quarter-sized zone and as a result rarely causes total
blindness in an eye. To put it another way, the central vision can be significantly
impaired by Macular Degeneration, but the remaining peripheral vision is
usually sufficient to allow persons to perform ease of movement in traveling
or moving about the house or office, and caring for children or grandchildren.
Persons with vision impairment from Macular Degeneration, however, may
need some type of low vision device for activities of daily living such
as shopping, reading mail, writing, or cooking.
It is important to understand more about the eye and how it works, as well as about structures in the retina and layers of tissue below the retina. A person must become familiar with these terms to more fully understand research findings and more complicated explanations of specific areas of the eye. |
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