Eye Diseases and Disorders FAQs
What is a cataract?
A cataract is a clouding of the lens in the eye that affects vision and is usually related to aging. Cataracts are very common in older people: more than half of all Americans over age 80 either have a cataract or have had cataract surgery. A cataract can occur in either or both eyes, and cannot spread from one eye to the other.
What causes cataracts?
The lens is of the eye is made mostly of water and protein. The protein is arranged in a precise way that keeps the lens clear and allows light to pass through. As we age, some of the protein may clump together, forming a cataract that starts to cloud a small area of the lens. In time, the cataract may grow larger and cloud more of the lens, making it ever harder to see.
Researchers suspect there are several causes of cataracts, such as smoking and diabetes. It also is possible that the protein in the lens simply changes as we age.
What is the lens?
The lens is a clear part of the eye that helps focus light on the retina. The retina is the light-sensitive tissue at the back of the eye’s interior.
In a normal eye, light passes through the transparent lens to the retina. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.
What is glaucoma?
Glaucoma is a condition in which the normal fluid that is produced by the eye doesn’t drain properly. Instead, the fluid collects, raising the pressure in the eye and damaging the optic nerve. The optic nerve is a bundle of nerve fibers that transmits visual information from the retina to the brain. This damage leads to loss of eyesight.
For more on this condition, read "Glaucoma: the Silent Thief of Sight" by Kimberly Miller, MD.
How can I keep my eyes healthy when I have to look at a computer screen all day at work?
Computer vision syndrome, also called digital eyestrain, may result from result from prolonged use of computers, tablets, e-readers and cell phones.
One simple way to alleviate digital eye strain is to adopt the 20-20-20 rule: Take a 20-second break to view something 20 feet away every 20 minutes.
Consult your ophthalmologist if you think you are suffering from computer vision syndrome. The symptoms include eyestrain, headaches, blurred vision, dry eyes, and neck and shoulder strain.
For more on eye strain, read "Five Tips for Managing Digital Eye Strain" by Aliya Zul Jiwani, MD.
What is macular degeneration?
Age-related macular degeneration (AMD) is a disease that affects a person’s central vision. AMD is the most common cause of severe loss of eyesight among people age 60 and older. Only the center of vision is affected with this disease. People rarely go completely blind from it. However, AMD can make it difficult to read, drive, or do other daily activities that need fine, central vision.
AMD happens when the macula begins to break down. The macula is located in the center of the retina and provides us with sight in the center of our field of vision. With less of the macula working, central vision begins to deteriorate.
What is conjunctivitis?
Sometimes called pink eye, this is an inflammation of the blood vessels in the conjunctiva, the membrane that covers the sclera (the white of the eye) and inside the eyelids. Conjunctivitis may be caused by bacteria or viruses, making it very contagious.