I often feel that my eyes ache when I look at the distance after reading for a long time. I will do some eye exercise at this moment to relax eye muscles. When we stare at the book or something else for a long time, our eyes will get used to this fixed distance. And there are less blinking during reading, so our eyes may suffer from dryness. We need to blink our eyes or apply some artificial tears to lubricate them. And our vision may seem to be blurry when we look at the distance, while this symptom will go away after several minutes because our eyes can adapt to the new distance quickly.