Hi ctulin,
Something you might want to try is a coloured foil to place infront of your comuter screen, or changing your screen brightness ratio. The light from the screen can fatigue your eyes faster than normal work. I had a student last year who didn't suffer from MG, but she would use coloured foils on the computer and over pages on her reading books. The lower contrast allowed her to relax her eye muscles and focus on what whe was reading. I'm not sure where you could purchase one, but if you are interested I'll find out where the school bought them.

Hope this helps! I's certainly no fun when you MG affects your work!
~Kathy