Definition
A cataract is a cloudy or opaque area in the normally clear lens of the eye. Depending upon its size and location, it can interfere with normal vision. Most cataracts develop in people over age 55, but they occasionally occur in infants and young children. Usually cataracts develop in both eyes, but one may be worse than the other. Reasearchers have linked eye-friendly nutrients such as lutein/zeaxanthin, vitamin C, vitamin E, and zinc to reducing the risk of certain eye diseases, including cataracts. For more information on the importance of good nutrition and eye health, please see the diet and nutrition section.

Causes
Most cataracts are due to age-related changes in the lens. However, other factors can contribute to their development including:

• Diabetes
• Medications
  • Corticosteroids
  • Chlorpromazine and other phenothiazine related medications
• UV
• Smoking
• Alcohol
• Nutritional deficiency: studies have suggested an association between cataract formation and low levels of antioxidants (e.g. vitamin C, E, carotenoids).

Symptoms
Cataracts generally form very slowly. Signs and symptoms of a cataract may include:

• Blurred or hazy vision
• Reduced intensity of colors
• Increased sensitivity to glare from lights, particularly when driving at night
• Increased difficulty seeing at night
• Change in the eye’s refractive error

Treatment
The treatment of cataracts is based on the level of visual impairment they cause.

In mild form, no treatment may be needed except for close monitoring. In some cases, a change in eyeglass prescription may provide temporary improvement in visual acuity. Increasing the amount of light used when reading may be beneficial. The use of anti-glare coatings on clear lenses can help reduce glare for night driving.

When a cataract progresses to the point that it affects a person’s ability to do normal daily activities, surgery may be needed. Cataract surgery involves removing the lens of the eye and replacing it with an artificial lens.