One of the most common causes of visual impairment as we get older is cataracts. Less than five percent of persons younger than age 65 will have cataracts. In contrast, 50 percent of individuals over age 75 will be diagnosed with this eye problem.
The eyeball was designed to allow reflected light from our surroundings to pass into our nervous system and brain. Our brain then interprets the light so that we can “see.” In order for this to happen, certain structures of the eye need to be transparent, allowing light to pass through uninterrupted to the retina. One of these important structures is the lens of the eye.
If you look at an eyeball, the first layer that light contacts is the cornea. The cornea is very thin and is entirely transparent. It allows light rays to enter the eyeball and pass through the front chamber of the eye. Light then proceeds through the pupil and reaches the lens.
The lens is another transparent structure that allows light to pass through it. However, it has an important and specialized function. It is a round, biconvex structure that is attached to muscles at its edges. These muscles allow the lens to become thicker or thinner in order to focus the light onto the retina at the back of the eyeball. The lens is composed mainly of water and proteins, this makes it elastic.
When these proteins “clump” within the lens, the lens forms an area of cloudiness. Any clouding or opacity within the lens that interferes with vision is called a “cataract.” Clouding can occur within the center of the lens (nuclear), the main portion (cortical), or on the outer surface of the lens (subcapsular). In any case, the cataract will cause a distortion in the light’s path to the retina.
The result is impaired vision. Most individuals with a cataract will complain of blurred vision. Other symptoms include glaring, halos around lights, poor night vision and double vision in one eye. Some will experience alterations in tinting, such as brown or yellow discoloration. These visual disturbances usually develop gradually and will progress over time.
The risk of developing cataracts increases as you get older. Mainly, it is just due to wear and tear on the eyes. Among the other risk factors for cataracts are: diabetes, a family history of cataracts, previous eye injury or inflammation, previous eye surgery, prolonged use of steroid medications, excessive exposure to sunlight or radiation and smoking.
Cataracts are diagnosed based on the individual’s symptoms, coupled with a thorough eye exam. Eye specialists can dilate the pupils to get a full view of the internal structures of the eye.
Treatment for cataracts is surgical. The lens is removed and replaced by an artificial lens. The procedure is the most common surgery paid for by Medicare. It is generally done as an outpatient and is both straightforward and highly effective.
Taking good care of your eyes includes getting proper rest, eating plenty of fruits and vegetables, wearing protective eyeglasses when appropriate (including sunglasses), avoiding smoking and getting periodic eye examinations.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.