Cataracts are easily distinguishable clouding of the eye’s lens. Cataracts can greatly interfere with an individual’s eyesight and, if not corrected, can cause blindness.
According to the Centers for Disease Control and Prevention (CDC), about 20.5 million Americans over the age of 40 either have cataracts in one or both eyes. It is expected that nearly 30 million Americans will have cataracts by 2020.
Causes of Cataracts
Cataracts occur when aging or injury affects the tissues in the lens of the eye (although there is also a congenital cataract that affects babies and small children). It is expected that, in addition to trauma to the eye, cataracts may have a genetic component, and it is expected that other health problems like diabetes, high blood pressure and obesity may also increase the risk of cataracts.
The lens, which is positioned behind the eye’s iris (the colored part of the eye), focuses all of the light that enters the eye and onto the retina, thereby allowing the eye to produce the crisp images many of us enjoy. When a cataract forms on the lens, however, the light that enters the eye scatters instead of focuses, thereby resulting in blurred vision.
In age-related cataracts, the tissue of the lens becomes thicker and less transparent, and the protein of the lens begins to break down and form small clumps, creating a cloudy appearance. Trauma-related cataracts involve damage to the lens, which also causes a breakdown and clumping of the protein of the lens. Cataracts can form in one or both of the eyes.
Symptoms of Cataracts
In addition to the telltale clouding over of the eye, many people with cataracts experience the following symptoms:
- Clouded, faded or dim vision
- Poor night vision
- Double vision in one eye
- Sensitivity to light and glare
- Experiencing “halos” around lights
- Frequent changes to eyewear prescription
Diagnosis of Cataracts
Anyone experiencing any changes to their vision should meet with their eye care professional. Through a thorough eye examination, which may include a visual acuity test, a dilated eye exam, and the use of a tonometry (a device that measures the pressure inside the eye), an eye care specialist (ophthalmologist) will likely diagnosis the individual with one of the following types of cataracts:
- Nuclear cataracts – Cataracts affecting the center of the lens
- Cortical cataracts – Cataracts that affect the edges of the lens
- Posterior subcapsular cataracts – Cataracts that affect the back of the lens
Treatment of Cataracts
Early cataracts generally are not removed unless they interfere with an individual’s ability to drive, read or perform other daily activities. Instead, many people benefit from a stronger eyeglass prescription, brighter lighting, or special anti-glare sunglasses.
Advanced cataracts (those that interfere with the ability to perform daily tasks, such as driving and reading) are usually removed through surgery. Cataract surgery involves removing the cataract-affected lens and replacing it with an artificial lens.
A healthy lifestyle that includes maintaining a healthy blood pressure and a healthy weight is often thought to decrease the likelihood of an individual developing cataracts. It is also expected that non-smokers have a lower chance of developing cataracts, as do people who eat an antioxidant-rich diet of leafy green vegetables and fruits. Further, many eye care specialists recommend protecting the eyes from ultraviolet sunlight damage using sunglasses and a wide brim hat.
Resources for Cataracts
- American Optometric Association
- International Glaucoma Association
- The American Academy of Ophthalmology