Kate,

Welcome to NeuroTalk. A variety of things could trigger symptoms long after an injury. Any kind of stress can be a trigger. Emotional, physical, chemical, and such can push your brain over the limit. Hormones can change and cause new symptoms based on the old injury.

Also, subtle injuries like a jarring step or trip, sleeping with your neck and head in a bad position, and little traumas that are usually ignored can be triggers. A fever or sneezing attack can be a trigger.

So, once concussed/brain injured, always susceptible to these triggers.

You are fortunate to have been seen by a knowledgeable ophthalmologist. Most patients would have been discounted as somatoform or such.

My best to you.