There's a good chance its due to dry eye. If so, you need to blink more. Get an eye compress (heat it up in microwave, toss on eyes for 10 minutes). That can help release oils from glands onto your eyes. Artificial tears can help with comfort but wont solve the underlying problem--we don't blink (enough) when we focus on screens that are close to our face.
I don't think that is the case but I could be wrong. My eyes do not feel dry at all and drops or hot washclothes haven't made much difference. Maybe that compress you speak of is better though
Hot wash clothes don't maintain the heat long enough to release the oils. Decent eye compresses are $20. Here's a decent one. Certainly others work too.
I got a fancier one from Tear Restore that has little cut outs, so I can see while using it (instead of keeping eyes closed). It may not work quite as good as the bruder, but it lets me get things done while using it.
