Have you had your eyes checked lately?

SATURDAY, June 6 (HealthDay News) -- Though good vision is what allows the perception of the colors, shapes and sights of the world, Americans appear to be fairly lackadaisical when it comes to protecting their eye health, according to surveys done by U.S. eye groups.

People who wear eyeglasses or contact lenses constitute 81 percent of the population, according to a survey done by the American Optometric Association.

But one of every five of them hasn't seen an eye doctor or eye-care specialist in more than two years, the recommended period between eye checkups, the survey found.

It's even worse for people who don't use corrective lenses. Of that group, three of every five haven't had a vision exam in more than two years.

Doctors believe this is because most vision problems aren't readily apparent and because people have enough on their plates without also having to schedule an eye exam.

"We're getting pulled every which way these days," said Dr. Andrew Iwach, an associate clinical professor of ophthalmology at the University of California, San Francisco, and a spokesman for the American Academy of Ophthalmology. "We're busy. For most of us, our vision is probably pretty good, we're getting along fine, and so we don't worry about it. And that comfort may lead to complacency."

A survey by the academy seems to support that belief. Only 28 percent of people surveyed felt they were at risk for any sort of eye disease, and just 23 percent said they were very concerned about losing their vision.

The problem with these perceptions is that most eye diseases come on subtly. Once someone recognizes vision loss, it's usually too late to have pursued many avenues of treatment, said Dr. Kerry Beebe, an optometrist in Brainerd, Minn., and a spokesman for the American Optometric Association.

"What we hear most of the time is, 'I'm not having any problems. My eyes don't hurt, and I think I see pretty good,' " Beebe said. "They don't realize a lot of eye diseases don't have any symptoms in the early stages, which is where you'd like to treat those kinds of problems."

For example, vision loss for people with glaucoma occurs at the edges of the visual field, Iwach said.

"By the time you realize something is wrong, a lot of vision loss has occurred," he said. "But if we catch it earlier, there's a lot we can do."

And, he says, eye doctors and eye-care specialists also might be able to catch other things that are wrong simply by peering into and testing someone's eyes.

"The eye is very unique," Iwach said. "It's the only place in the body we can see a bare vein, artery and nerve. We can actually see the back of the eye and the optic nerve. This can give us clues and tips that there might be other systemic diseases going on."

For example, some problems of the eye can serve as early warning signs of diabetes, he said.

The American Optometric Association recommends that adults get their vision checked at least every two years, even if they don't perceive any problem with their sight. Children should have their vision tested at 6 months of age, 3 years old and right before they enter first grade and then every two years thereafter.

The association's survey found that eight of 10 kids aren't getting that first vision test by age 1. "Parents figure they must see fine, they aren't complaining, and I don't see a problem," Beebe said. "But kids have no base to compare what they're supposed to be seeing. They can't tell something's wrong."

You also should see an ophthalmologist at least once by age 40, according to new guidelines set by the American Academy of Ophthalmology. Ophthalmologists are medical doctors who have specialized in eyesight and are the best-trained of all eye-care providers. "It puts us in an ideal position to make assessments of risk," Iwach said.

Having had that baseline examination by 40, an ophthalmologist is then in a good position to track a person's sight as age-related problems such as cataracts or macular degeneration threaten sight.

"We so rely on our eyes," Iwach said. "We so enjoy our vision and what it brings to us. It doesn't require much maintenance, but if we don't provide at least a minimum amount of scheduled maintenance, it can lead to later vision loss."