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FRIDAY, Aug. 8 (HealthDayNews) -- Today almost 20.5 million Americans 40 and older have cataracts, and half of all Americans will develop them by the time they reach 80.

August is Cataract Awareness Month. Betsy van Die, a spokeswoman for Prevent Blindness America, says, "We are stressing that for older people regular eye exams are important, and for everyone there are things you can do to help prevent the early development of cataracts."

Dr. Peter Whitted, from the Midwest Eye Center in Omaha, Neb., says the question for patients is when do cataracts get in the way of their daily activities.

"Cataracts should be removed when it affects your lifestyle significantly enough that you cannot accomplish the tasks you want to accomplish," Whitted says. "Rarely does a cataract have to be removed for medical reasons."

Whitted notes studies have shown that cataract removal significantly improves quality of life -- "which is the point of cataract surgery."

A cataract is a cloud that appears over the lens of the eye. It is "a normal aging process of the eye," says Dr. Shachar Tauber, director of cornea external disease and refractive surgery and an assistant professor of medicine at Yale University School of Medicine. "Cataracts slowly but surely rob people of quality vision affecting daily activities, as vision is lost due to clouding of the lens of the eye."

Risk factors for cataracts include exposure to heat, long-term exposure to ultraviolet rays, smoking, diabetes, long-term steroid use -- including inhaled steroids -- and eye injuries.

"Diabetes affects the metabolism in the eye, so patients who have blood sugars that fluctuate develop swelling in the eye, which becomes cataractous. The bigger problem is that these cataracts can block the view of the retina and hide other, more serious eye problems," Tauber says.

Smoking promotes cataracts by interfering with the eye's antioxidant defense mechanisms. Patients who are quitting smoking should use antioxidants, particularly vitamin E, Tauber notes. He also stresses limiting exposure to UV rays.

All seniors will be affected by cataracts, Tauber, says. "Some seniors tolerate it just as 'My eyes are old.' That's the classic thing we hear from patients," he notes. "Yes, they're old because they develop cataracts."

While cataract surgery is now about 95 percent effective, Tauber says that Medicare reimbursement is not adequate to make the most up-to-date techniques viable for many older patients. These newer techniques are readily available in Europe and South America, he adds.

Cataract surgery is one of the safest procedures, Tauber says. "Cataracts will occur in the majority of people over time, but they shouldn't be afraid of cataracts and they shouldn't ignore them, because there are excellent treatments that effectively restore quality of life."

More information

To learn more about cataracts, visit the National Eye Institute or Prevent Blindness America.