Intermittently for the last couple of days, each of my eyes has been having difficulty "agreeing" on the same thing to focus on. For example, if I hold up a pencil in front of me, one eye will be focused on the pencil, and the other will be focused slightly beyond or in front of it.

The result is that I can't really see for stretches at a time.

My (corrected) vision is otherwise fine; if I cover up one eye, I can see out of the other with no problems.

This new thing is really distressing.

Has this happened to anyone else? Who should I see about it? I'm not even entirely sure what the difference between an ophthalmologist and an optometrist is. But since I have PCS, I am thinking it is more of a brain thing anyways.