A cataract is a cloudy area in the lens or lens capsule of the eye. A cataract blocks or distorts light entering the eye. This causes problems with glare from lamps or the sun. Vision gradually becomes dull and fuzzy, even in daylight. Most of the time, cataracts occur in both eyes, but only one eye may be affected. If they form in both eyes, one eye can be worse than the other, because each cataract develops at a different rate. When cataracts are forming, vision can be helped with frequent changes in eyeglass prescriptions.
There are several causes of cataracts:
- Senile cataracts are the most common form. These cataracts result from aging. This is probably due to changes in the chemical state of lens proteins. About half of Americans aged 65 to 74 have cataracts. About 70 percent of those over 75 have this condition.
- Traumatic cataracts. These develop after a foreign body enters the lens capsule with enough force to cause specific damage.
- Complicated cataracts. These occur secondary to other diseases (e.g., diabetes mellitus) or other eye disorders (e.g., detached retinas, glaucoma, and retinitis pigmentosa). Ionizing radiation or infrared rays can also lead to this type of cataract. Also, a baby can be born with cataracts in one or both eyes if its mother had German measles (rubella) when she was pregnant.
- Toxic cataracts can result from medicine or chemical toxicity. Smokers have an increased risk for developing cataracts.
Signs and Symptoms
- Cloudy, fuzzy, foggy, or filmy vision
- Sensitivity to light and glazed nighttime vision. This can cause problems when driving at night because headlights seem too bright.
- Double vision
- Pupils which are normally black appear milky white
- Halos which may appear around lights
- Changes in the way you see colors
- Problems with glare from lamps or the sun
- Better vision for awhile, only in farsighted people. This is called “second sight.”
Prevention
- Limit exposing your eyes to X-rays, microwaves, and infrared radiation.
- Use sunglasses that block ultraviolet (UV) lightboth UVA and UVB rays.
- Wear a wide-brimmed hat or baseball cap to keep direct sunlight from your eyes while outdoors.
- Avoid overexposure to sunlight.
- Wear glasses or goggles that protect your eyes whenever you use strong chemicals, power tools, or other instruments that could result in eye injury.
- Don’t smoke.
- Avoid heavy drinking.
- Eat a lot of foods high in beta-carotene and/or vitamin C, which are thought to help prevent or delay cataracts. Carrots, cantaloupes, oranges, and broccoli are examples of such foods.
- Follow your doctor’s advice to keep other illnesses such as diabetes under control.
- For females: Get a vaccination for German measles if you haven’t had them and if you plan on getting pregnant.
Treatment and Care
If the vision loss caused by a cataract is only slight, surgery may not be needed. A change in your glasses, stronger bifocals, or the use of magnifying lenses and taking measures to reduce glare may help improve your vision and be enough for treatment. To reduce glare, wear sunglasses that filter both UVA and UVB rays when you are outdoors. When indoors, make sure your lighting is not too bright or pointed directly at you. Use soft, white light bulbs instead of clear ones, for example, and arrange to have light reflect off walls and ceilings. When cataracts interfere with your life, however, surgery should be considered.
Modern cataract surgery is safe and effective in restoring vision. Ninety-five percent of operations are successful. For the most part, surgery can be done on an outpatient basis or involve no more than an overnight hospital stay.
A person who has cataract surgery usually gets an artificial lens at the same time. A plastic disc called an intraocular lens is placed in the lens capsule inside the eye. Other choices are contact lenses and cataract glasses. Your doctor will help you to decide which choice is best for you.
It takes a couple of months for an eye to heal after cataract surgery. Experts say it is best to wait until your first eye heals before you have surgery on the second eye if it, too, has a cataract.
Following surgery, continue to protect your eyes by wearing sunglasses that filter both UVA and UVB rays.