The ability to see is often taken for granted. Too few Canadians recognize the role proper eye care and regular eye examinations play in maintaining the vision upon which they rely.

In fact, people tend to believe that as long as their vision is good, their eyes are healthy. But not all forms of eye disease involve symptoms, says Derek MacDonald, an optometrist in Waterloo, Ont., and former president of the Ontario Association of Optometrists.

“Don’t assume that just because you’re seeing well, your eyes are healthy,” says MacDonald, who is involved in the Canadian Association of Optometrists’ national public education campaign promoting regular eye examinations.

In most provinces, public health insurance does not cover regular eye examinations for adults between the ages of 20 and 64, with the exception of those with diabetes, glaucoma, cataracts or certain other health problems. As a result, Canadians whose costs are not covered may avoid visiting their eye doctor unless they experience perceptible vision problems.

But studies show that among adults who have their eyes tested, 15% of those with no concerns about their vision are diagnosed with some form of eye disease. Without an examination, such problems can remain undiscovered until they cause significant damage.

Glaucoma, for example, is becoming increasingly prevalent. Known as the “silent thief of sight,” it involves no symptoms until the late stages of the disease; it ultimately causes blindness.

More than 250,000 Canadians have glaucoma and at least half don’t realize it, says Dr. Neeru Gupta, a professor of ophthalmology and vision sciences at the University of Toronto and director of the glaucoma unit at St. Michael’s Hospital in Toronto.

Glaucoma is generally associated with elevated pressure in the eye, and becomes a greater risk in old age. It usually first affects a person’s peripheral vision, which means an adult with advanced disease can still have 20/20 vision, Gupta says. The disease can take up to 15 years to lead to blindness, and any sight impairment it causes is irreversible.

“It’s very common,” Gupta says, “to see patients who have lost much of their vision and who had no idea that they had glaucoma.”

By diagnosing glaucoma early, however, treatment can be initiated that slows the progression of the disease and prevents damage. In most cases, Gupta says, early treatment of glaucoma prevents blindness. This is one reason it’s crucial for even healthy adults with no vision problems to have their eyes checked periodically.

“You can’t know whether you have the disease or not,” Gupta adds, “without an eye examination.”

Age-related macular degeneration is another eye disease that can come without noticeable symptoms and for which early detection is crucial. AMD, a progressive condition that attacks central vision, is the leading cause of vision loss in adults over the age of 50, affecting one million Canadians.

As Canada’s population ages over the next 35 years, the incidence of AMD is expected to double, says the Canadian National Institute for the Blind, a Canadian charity involved in research and public education on vision health.

While there is no cure for AMD, early diagnosis through an eye examination means there are more options for treatment, which can stabilize vision. At later stages, the CNIB says, treatments are often less effective.

MacDonald recommends that healthy adults have their eyes checked every two years — with certain exceptions. For example, he urges patients who wear contact lenses to see their optometrist at least once a year, since contacts can cause complications — sometimes, serious ones.

As well, those at greater risk of developing eye disease — seniors, people with a family history of eye disease and those who suffer from diabetes — should see their optometrist more frequently and be examined annually, at least.

Adults with other health problems are also more likely to encounter eye problems. “We’re learning more and more,” MacDonald says, “that your eye is really affected by general health and lifestyle decisions.”

Cigarette smoking, for instance, makes adults more prone to eye disease. The risk of developing AMD is 600% higher for adults who smoke.

Diet is another factor that can affect the health of your eyes. Accord-ing to Health Canada, a daily dose of the vitamins and minerals found in melons, citrus fruit, carrots, spinach and kale can slow the progress of age-related eye diseases. Research also shows that high consumption of the fats found in junk foods can boost the risk of developing AMD. IE