Cataracts are a normal part of aging. About 75% or 3 out of 4 people over 65 have some form of cataracts. About 90 percent of those aged 75 and over have this condition. In Armenia, cataract is the leading cause of blindness.
A cataract is a clouding of the eye’s lens that causes loss of vision.
The lens lies behind the iris and the pupil (see diagram). It works much like a camera lens. It focuses light onto the retina at the back of the eye, where an image is recorded. The lens also adjusts the eye’s focus, letting us see things clearly both up close and far away.
The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and allows light to pass through it. But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see.
The term “age-related” is a little misleading. You don’t have to be a senior citizen to get this type of cataract. In fact, people can have an age-related cataract in their 40s and 50s. But during middle age, most cataracts are small and do not affect vision. It is after age 60 that most cataracts steal vision.
Eye injuries can cause a cataract to form. For example, a severe blow to the eye, which results in a ruptured globe. Or, a piece of metal from a grinding wheel or a sledge hammer, which penetrates the cornea and lens of an unprotected eye.
An inflammation inside the eye – iritis or uveitis – and can cause cataract formation. This usually results after several episodes of inflammation or after a prolonged episode of untreated inflammation.
A cataract starts out small. It has little effect on vision at first. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass.
A cataract may make light from the sun or a lamp seem too bright, causing a glare. Or, you may notice when you drive at night that the oncoming headlights cause more glare than before – or are blinding and cause you to see “halos.” Also, colors may not appear as bright to you as they once did.
As the cataract gets bigger and clouds more of the lens (doctors use the term, “ripens”), you will find it harder to read and do other normal tasks. The word “cataract” means waterfall. For people with a ripe cataract, it is like trying to see through a waterfall.
Although you might think you have a cataract, the only way to know for sure is by having an eye examination. Should your eye care professional find one, he or she can monitor it and advise you about any future treatment.
It is treated with surgery. Your eye care professional will remove your clouded lens and, in most cases, replace it with a clear, plastic lens. Cataract surgery is very successful in restoring vision. In fact, it is one of the most common surgeries performed in the United States, with over 1.5 million cataract surgeries done each year.
If your eye care professional finds a cataract, you may not need cataract surgery for several years. There is a danger in delaying treatment or waiting too long to have a cataract removed. Advanced (ripe) cataract can severely reduce vision and may be associated with the development of glaucoma. Cataracts are also easier to remove in the early stages. Better surgical techniques are available than with “ripe” cataracts and there is less risk with the procedure. By having your vision tested regularly, you and your eye care professional can discuss when you will need treatment.
How is vision restored following cataract surgery? When the eye surgeon removes the cataract she is removing the clouded lens, which when clear focuses images on the retina. Without the powerful lens, vision is blurred until the magnification is restored. There are three ways this is accomplished.
These are thick eye glass lenses that restore vision, but with a great degree of enlargement of what is seen through the lenses.
Contact lenses restore vision, but must be worn daily and removed before sleep to prevent eye irritation. Vision is restored to near-normal, but contact lenses can be difficult to apply and wear, particularly for the older person.
A small, clear plastic lens is implanted into the eye where the clouded lens with a cataract was removed. Vision is restored to near-normal and usually no follow-up care or additional surgeries are required. Occasionally, a clouding of the lens may occur within one to three years. This can be easily opened and removed with a rapid laser procedure.
If you are over age 60, you should have an eye examination at least once every two years. This exam should include dilating your pupils. This means drops are put into your eyes to enlarge your pupils. Although a cataract can be detected without dilated pupils, your eye care professional can see the back of your eye better using this exam. Getting a good view of the retina and optic nerve is important in detecting eye diseases such as glaucoma and macular degeneration.