For the sake of your other body parts: lower back, neck, wrists

take breaks and do little exercises

http://www.slifelabs.com/

http://www.floydprice.com/2008/08/productivity-tip/

http://bc.tech.coop/blog/060131.html

http://www.workrave.org/

http://www.lcdf.org/~eddietwo/xwrits/

http://cameronyule.com/2008/11/taking-regular-breaks

Used to be 20/20 w/ an astigmatism and never needed glasses. After working w/ computers for about 7-8 yrs, I went to the eye doctor to complain about my eyes hurting. Strangely enough I still have 20/20 vision yet, due to eye strain, my eyes have trouble compensating for the "fuzziness" of fonts; the doc said that my eyes try to smooth them out. I got a mild prescription and it's great. No worse after 3+ years.

Coupla protips: * Don't code on a white background - hurts/strains the eyes moreso than a gray bg

* Buy a great monitor - $100 more in cost isn't worth saving if you lose x% of eyesight or have pain.

I keep eye drops at my desk and usually around 3pm I'll stop and use them, otherwise my contacts get to be super dry and painful.

Not wearing any galsses. Still no problem with eyes.