Been expiriencing double vision. goes away if i cover either of my eyes. not constant. optometrist didn't find anything wrong. any ideas?

There is a reason: Double vision that goes away when you cover either eye means there is a problem with the alignment of your eyes. It could mean a decompensation of a longstanding or even a congenital problem. Or, it could mean something more serious. There is "something wrong" as there is a reason for this. I would suggest a second opinion with an Ophthalmologisr, a medical doctor who specializes in eye disease