I've read that putting a light behind your monitor helps relax the eyes (i.e. illuminating the wall around the edges of the monitor) -- and it seems to work OK

I've read that putting a light behind your monitor helps relax the eyes (i.e. illuminating the wall around the edges of the monitor) -- and it seems to work OK for me. I think the theory is that it increases the amount of light entering the eye peripherally, which contracts the pupil slightly, helping focus.