With special thanks to Dr. Ben Wild, of FYidoctors, for sharing his expertise.

Eye exams, like dental and medical check-ups, are an important part of maintaining our physical health. But, for many, they’re also the first to signal that a patient may have a brain tumour.

“It’s probably once a year, on average,” says Dr. Ben Wild, an optometrist at FYidoctors in Ottawa, of how often he detects an abnormality that leads to a brain tumour diagnosis. “I’ve gone a few years without seeing one, and then in the last year, I’ve seen three.”

The importance of routine eye exams

Sometimes, the patient has been experiencing symptoms, such as blurred or double vision, loss of vision, sensitivity to light, blind spots or changes in normal eye movements. Most times, however, abnormalities are found during routine eye exams.

“In all cases I’ve seen, except for one, they didn’t know something was going on,” Dr. Wild says.

He describes a patient who noticed a blind spot, in the same location, in each eye, and another who had been prescribed glasses from their optometrist only to find they weren’t improving his vision.

“He came to us for a second opinion,” Dr. Wild says, “and as soon as he sat in the chair and started reading the chart in front of him, he was only reading half of it with each eye. I thought, ‘Oh, I know what’s happening.’”

Next, Dr. Wild gave him a visual field/peripheral vision test to look for blind spots.

“Sure enough, this person couldn’t see anything to the right from their right eye and couldn’t see anything to the left from their left eye,” he says. “We sent him to the hospital right away and it turns out he had a pituitary tumour in his brain.”

What optometrists look for

Blind spots are primarily what suggest to optometrists that something more may be going on. The visual field/peripheral vision test measures exactly where those blind spots are, giving the optometrist a good idea of where in the brain a lesion might be.

“It could be a brain tumour, it could be a brain aneurysm, it could be anything that’s not supposed to be there,” says Dr. Wild.

Another thing optometrists look at is the optic nerves at the back of the eye.

“If they’re swollen, that means the entire brain is swollen,” says Dr. Wild.

Tumours can cause pressure in the skull, which may lead to brain swelling. If an optometrist suspects this is happening, they’ll refer an individual to the hospital right away for brain imaging.

How the eyes reflect your overall health

“More than half the cranial nerves that control the entire body have some effect on the eye,” Dr. Wild says, “so you can determine a lot about neurological health through that. Also, the eye is one of the only places in the body where you can see functioning blood vessels and a functioning cranial nerve without cutting into the skin. That’s why often, the first time noticing a neurological condition, like a tumour, or a vascular condition, like blood pressure or diabetes, or even an autoimmune condition, is through an eye exam.”

From there, optometrists will send patients for further testing. Alberta, Dr. Wild notes, is the only province that allows optometrists to order bloodwork.

When should you schedule an eye exam?

Even if you don’t have any eye concerns, you should see your optometrist regularly.

For healthy adults between 19 and 40, that means every three years or so. From 40 to 65, when more vision changes tend to happen, Dr. Wild recommends every two years. After age 65, many will need annual visits, which is also what Dr. Wild suggests for children up to age 18.

Many provinces offer free eye exams for children, so check the regulations where you live or ask your optometrist’s office when booking. If finances are holding you back, there are programs that can ease the cost.

An eye exam is about more than just vision—it’s a vital window into your overall health. By making regular visits to your optometrist, you’re not only protecting your sight, but also giving yourself the best chance to catch serious health conditions, such as brain tumours, early.