My guess would be that you are having trouble with convergence. That is coordinating the eyes to look at a point close to your face.

You might want to get checked for convergence insufficiency by a provider listed at http://www.braininjuries.org or http://www.nora.cc

You could do an informal test by holding your finger out and trying to follow it close in to the point of your nose. If that hurts or you are unable to do it, you probably are having convergence problems.

This type of problem could also show up in close activities like reading.