Regular eye exam

Vision problems, such as nearsightedness, farsightedness or astigmatism, affect half of all Americans 20 years or older, said a research team at the National Eye Institute.

The study involved analyzing data from the National Health and Nutrition Examination Survey, which covered the period 1999 to 2004 and involved more than 12,000 people of both sexes, aged 20 and older.

Nearsightedness, or myopia, and astigmatism, an irregular curvature in the shape of the cornea which results in distorted or blurred vision, are the most common problems. The analysis showed that about 33 percent suffered from nearsightedness, and a little above 36 percent had astigmatism. A small proportion, 3.6 percent, had farsightedness.

There were slight differences among the sexes. Among those aged 20 to 39, nearsightedness was more common among women (with about 40 percent) than men (close to 33 percent). But in those aged 60 and older, about 66 percent of men suffered from refractive problems while only 59 percent of women had them.

These three eye conditions, where the eye has difficulty achieving the proper focus, are collectively called “refractive errors.” They affect people of all races and of all ages.

The 50 percent overall incidence of vision problems is far higher than the 25 percent estimated incidence in previous studies, stated the team in its report published Monday in the Archives of Ophthalmology.

This may indicate that problems associated with refractive errors are on the rise among Americans. This is particularly true in the case of nearsightedness.

The findings in this study match results of studies in other countries where about one half of the adult population suffer from refractive eyesight errors. These conditions are usually corrected by prescribing eyeglasses or contact lenses, and corrective surgery.

In the United States, the direct cost of treatment for these eye problems is between $3.8 and $7.2 billion a year, according to some estimates.

A separate study that appeared in the same journal reported that Americans who do not have health insurance are less likely to have their eye problems attended by medical professionals. Only 42 percent of those without insurance see a doctor while 67 percent of those who have insurance seek medical attention.

The underlying causes of refractive errors are not clear. Heredity plays a part. But several professors of ophthalmology hazard the guess that the rising incidence of vision problems today may be related to widespread use of computers and TV, as well as video games among the younger generation.

Safety Tip:

* Limit continuous exposure of the eyes to computers, TV and video games. These are very strenuous on the eyes. Allow the eye to rest a bit after half an hour of exposure.