Concussions can cause all kinds of unpleasant side effects – nausea, headache, dizziness, and blurred vision just to name a few. However, some of these symptoms can be caused by a very specific syndrome affecting concussion patients.

Post-trauma vision syndrome is a very specific syndrome to patients who have suffered a concussion.

Optometrist Dr. Toby Mandelman says we have two components to our vision system: the focal system is used to read or determine what something is and the ambient system provides the peripheral awareness to use the focal system.

“When people have damaged that part of the vision system, it causes some very specific symptoms,” says Mandelman.

Symptoms like delayed reaction time, difficulty with visually stimulating environments, a tilted centre of gravity causing balance issues, and the inability to walk in a straight line.

Derrick Zimmerman sees double and has trouble walking in a straight line.

“I was blaming the poor dog for walking into the dog, or the dog walking into me, where in fact I was falling into the dog,” says Zimmerman.

His vision problems started after a concussion he suffered this summer and he's had others in the past. He now sees the eye doctor eager to correct the problem.

“I'm hoping to be able to see properly, really, that's what the bottom line is, walk straight,” says Zimmerman.

For Heather Crosby Gionet, her symptoms interfered with her work as a photographer and daily life.

“Every day I would end up with an awful, awful headache. Some days into what I thought was a migraine. You know, it was just debilitating. I was throwing up and it was just awful and I just couldn't live my life,” says Crosby Gionet.

Mandelman fitted Crosby Gionet with special blue-tinted glasses to help her focus and to correct her crooked walk.

“We put something called yoked prism in their glasses and that straightens out that tilt that they have and it basically turns the world straight again for them so they don't have to think so hard about keeping their balance,” says Mandelman.

“When she put the little trial pair on with the prescription in it, I was like 'this is a whole new world, like I can see again,’” says Crosby Gionet.

Dr. Linda Ferguson runs a concussion clinic. She treats patients who aren't getting better after four to six weeks and says about 60 per cent of those patients have PTVS.

“If you don't identify it and treat it, all the rest of the therapies won't work,” says Ferguson. “Once their visual world comes back to normal, then we can actually start doing other therapies such as physiotherapy, occupational therapy, neuropsychology.”

Patrick Thompsonis a physiotherapist who works with concussion patients, including Crosby Gionet. He sees the benefits of treating vision problems first hand.   

“Some of these people are quite severely affected and it's hard to do therapy on somebody who it's difficult for them to walk down the street even, so it really enables us to do a little bit more complex work,” says Thompson.

Dr. Mandelman says the goal of her work, combined with the other therapies, is to rehabilitate the ambient system, returning the centre of gravity to the middle, and allowing eyes to focus properly.

“If all that happens, and it's usually three to six months later that they are recovered, they come back to see me, I reassess them, and often times I'm taking the prism back out of their glasses, sometimes they don't even need glasses at all anymore,” says Mandelman.

Mandelman says the success of the treatment often depends on how long ago the injury occurred, the age of the patient, and the severity of the concussion. She says about 5 per cent of patients have an amazing response, about 80 per cent respond really well, and about 15 per cent don't respond at all.