It is certainly possible that your changes in vision are due to your concussion. It's very important to keep your prescription up to date and wear the appropriate corrective eyewear. I had a small change in my prescription and changing to new glasses made a big difference in helping to alleviate my symptoms. There are a number of other cases of people noticing significant improvement after getting the appropriate corrective lenses. However, sometimes that means getting special prism lenses to correct for double vision and convergence problems.