text: Every 15 minutes or so, look away from the book and focus on something far away for about 30 seconds.  Our eyes are normally "binocular", and when we read, they become "monocular", focusing on one close thing.  \n\nAlso, try this:  Rub your hands together until they're warm.  "Palm" your eyes--that is, place your hands over your eyes, but don't put pressure on them.  Then imagine you're looking at something far, far away; you'll feel the focus changing in your eyes, while the heat will help relax the muscles around them.