I don't know if it's of any help but a good mate of mine suffered from a similar condition and has been on extended leave from his employee. After extensive tests which showed nothing out of line it was finally discovered that his right eye was not giving the correct signals to his brain. Apparently it was a matter of "training" his right eye again.
You have to forgive me if it's not completely factually correct but that was how he had explained it to me several months ago.
Hope this helps.
