Is it bad to massage my eyes when they get tired from computer use?

In a word, yes: Normal eye pressure runs about 10-20mmhg. Anything higher gives doctors pause to consider glaucoma. Rubbing eyes can increase the pressure as high as 60mmhg - 3 times the upper limit. This can cause a glaucoma-like condition over years. Additionally, some studies suggest that chronic eye rubbing can lead to other vision problems. Better to use artificial tears to soothe your tired eyes.

Eye fatigue: I don't recommend rubbing or massaging your eyes after fatigue induced by computer use. It's best to give your eyes a break every 50' on the hour, to use artificial tear drops, and to stare away from the computer screen.

Dry eye: Your eyes are getting dry while you are using the computer. Instead of massaging your eyes, try using artificial tears and taking a short break if possible. Warm compresses of the eyelid are fine but i would avoid firm massaging of your eyes themselves.