A cataract is an opacification or cloudiness of the eye’s crystalline lens due to aging, disease, or trauma that typically prevents light from forming a clear image on the retina. Cataracts often develop slowly and can affect one or both eyes. It cannot spread from one eye to the other. Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. About 20 million people are blind due to cataracts. Researchers suspect that there are several causes of cataract, such as smoking and alcohol, diabetes, radiation or, it may be that the protein in the lens just changes from the wear and tear it takes over the years. Symptoms may include faded colors, blurry vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces.
The symptoms of early cataract may be improved with new eyeglasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens. Surgery is needed only if the cataracts are causing problems and generally results in an improved quality of life. Cataract surgery is very successful in restoring vision. The procedure typically is performed on an outpatient basis and does not require an overnight stay in a hospital or other care facility. The operation usually lasts less than one hour and is almost painless. Many people choose to stay awake during surgery. Others may need to be put to sleep for a short time.
Adults are usually awake for the procedure. Numbing medicine (local anesthesia) is given using eye drops or a shot. This blocks pain. Children usually receive general anesthesia. This is medicine that puts them into a deep sleep so that they are unable to feel pain.
The doctor uses a special microscope to view the eye. A small cut (incision) is made in the eye.
The lens is removed in one of the following ways, depending on the type of cataract:
- Phacoemulsification: With this procedure, the doctor uses a tool that produces sound waves to break up the cataract into small pieces. The pieces are then suctioned out. This procedure uses a very small incision.
- Extracapsular extraction: The doctor uses a small tool to remove the cataract in mostly one piece. This procedure uses a larger incision.
- Laser surgery: The doctor guides a machine that uses laser energy to make the incisions and soften the cataract. The rest of the surgery is much like phacoemulsification. Using the laser instead of a knife (scalpel) may speed recovery and be more accurate.
After the cataract is removed, a manmade lens, called an intraocular lens (IOL), is usually placed into the eye to restore the focusing power of the old lens (cataract). The doctor may close the incision with very small stitches. Usually, a self-sealing method is used.
For a few weeks after surgery, doctor may ask to use eye drops to help healing and decrease the risk of infection. In most cases, healing will be complete within eight weeks.