Eye Conditions
 Perhaps you've just gotten home from the doctor and learned that you have macular degeneration. Or maybe you've recently heard that your friend needs cataract surgery. Whatever your experience, there's a chance that you're looking for more information. For each of the eye conditions listed on the left, you'll find basic information as well as links to the medical world for more detailed information. Please remember that the general descriptions here only provide a simple introduction to eye diseases and conditions. Signs and symptoms can vary from person to person, and it is best to consult a vision specialist to discuss concerns you may have. Low Vision: An introductionWhat is low vision?Low vision is a general term used to describe partial sight. Sometimes people refer to low vision as being “hard of seeing” or “a little bit blind.” Low vision is when your vision no longer meets your needs, and even your prescription eyeglasses don’t make your vision clear. Low vision can range from tunnel vision to blind spots to “legal blindness” to almost total blindness. Census 2000 reports that one in seven American people 65+ report some form of vision impairment. What is legal blindness?Legal blindness is typically defined as visual acuity of less than 20/200 in the best eye with the best correction (glasses or contact lenses). This means that what a healthy eye can see from 200 feet, the legally blind individual must be 20 feet away to see the same object. Legal blindness can also refer to a visual field of less than 20 degrees, or tunnel vision. Fewer than 10% of people in this group are totally blind. What are the leading causes of low vision and vision loss?Age-related macular degeneration is the most common cause of low vision for people over 50, accounting for almost 45% of all cases of low vision. Glaucoma is the second leading cause of low vision, and is the number one cause among African-Americans. Macular degenerationThe macula is the tiny area in the middle of the retina that is responsible for seeing fine detail. As people age, the macula can become damaged, causing a gray or blank spot to appear in the center of the visual field. Age-related macular degeneration is the leading cause of vision loss in Americans over 50. For more information on macular degeneration, see:
GlaucomaGlaucoma is a group of diseases that damage the optic nerve due to increased fluid pressure in the eye. The fluid in the inner eye normally drains in and out. When the fluid in the inner eye can no longer drain properly, the pressure in the inner eye slowly increases. This pressure eventually causes damage to the optic nerve, triggering sight loss. Sight loss usually begins with the peripheral vision, causing “tunnel vision." If left untreated, glaucoma can cause blindness. Glaucoma is the second most common cause of blindness on the United States, and the leading cause of blindness for African-Americans. For more information on glaucoma, see:
CataractsA cataract occurs when the lens of the eye becomes cloudy. With cataracts, eyesight becomes “hazy” and washed out. Colors and detail become more difficult to see, and surgery to replace the lens may become necessary. About half of all Americans between 65–75 have cataracts to some degree. For more information on cataracts, see:
Diabetic retinopathyDiabetic retinopathy is an eye complication as a result of diabetes. Diabetic retinopathy occurs when the blood vessels in the retina either leak fluid or grow abnormally. These changes cause scattered “blind spots” to appear, and vision can vary from day to day. The longer a person has diabetes the greater the likelihood of developing diabetic retinopathy, so frequent eye exams are important. For more information on diabetic retinopathy, see:
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