Anecdotal evidence is virtually useless*, but my wife suffered from double vision for a year after a bike accident, then it suddenly corrected itself (as the doctors thought it might, rather than take action), and has not recurred in the several years since. Brains and eyes are tricky, and while I doubt Joe is suffering from something as overt as my wife had, because they'd shut him down if only for his own safety everywhere on the field, it still could be that a month or a year from now Joe wakes up and starts being Joe again. *When did that ever stop me?