THURSDAY, March 12, 2020 (HealthDay News) -- As the population ages, millions of older Americans are at risk of losing their sight, a new study warns.

Between 2002 and 2017, the number at high risk for vision loss rose from 65 million to 93 million, according to federal health data.

"The number of adults at high risk for vision loss is high and may continue to increase in the coming years with the increasing population of adults over 65 years and prevalence of diabetes," said study lead author Sharon Saydah. She's a senior scientist at the U.S. Centers for Disease Control and Prevention.

"While the percent of adults at high risk for vision loss who receive eye care services has increased, disparities in eye care services by education level and poverty status persisted over time," she said. "Reasons for these disparities are not understood."

Besides seniors, those at high risk of losing their sight include people with diabetes and anyone with eye or vision problems.

About 57% of the more than 30,000 adults who participated in nationwide government health surveys in 2002 and 2017 said they had a yearly eye exam. Nearly 60% said their exam included dilating their eyes, which gives doctors a better view of the back of the eye.

But nearly 9% of those who needed eyeglasses said they couldn't afford them, the researchers found.

For the study, Saydah and her team used National Health Interview Survey data.

According to Dr. Barbara Horn, president of the American Optometric Association, "Eye exams are essential health care that safeguards vision and saves lives." And a routine comprehensive eye exam does much more than a generic vision test, she said.

"A doctor of optometry ensures the eye's health and can identify more than 270 systemic diseases, including diabetes, hypertension [high blood pressure], cancer and stroke, before exhibiting symptoms," Horn said.

In 2018 alone, more than 300,000 Americans were diagnosed with diabetes through an eye exam, she noted.

"With an aging population and increased prevalence of diabetes, it's more important than ever to educate the public on the importance of annual comprehensive eye exams," Horn added.

Dr. Mark Fromer, an ophthalmologist at Lenox Hill Hospital in New York City, said the conditions that most affect older people's vision are diabetes, glaucoma, cataracts and macular degeneration.

"Every decade of life, you're at an increased risk for all of those issues," he said, pointing out that an estimated 50 million baby boomers are aging into the high-risk years.

The good news? All of these conditions are treatable -- and covered by medical insurance, including Medicare and Medicaid, Fromer said.

But regular eye exams aren't covered unless you have diabetes or other vision problems. Nor are eyeglasses, usually. Some Medicare Advantage plans do cover eye exams and part of the cost of glasses, Fromer said.

He recommends yearly eye exams to ensure that any problems are caught early.

"Even if your eyes feel relatively good, you should see your ophthalmologist," Fromer advised, "because there are certainly issues at work where a patient could lose vision."

The report was published online March 12 in JAMA Ophthalmology.

More information

To learn more about vision loss, visit the U.S. Centers for Disease Control and Prevention.