Muscle strain is caused by keeping a static load on a muscle for a while without enough breaks to relax and recover. Both focusing and convergence of the eyes

Muscle strain is caused by keeping a static load on a muscle for a while without enough breaks to relax and recover. Both focusing and convergence of the eyes require muscle contraction, and can lead to eye strain. Moving work a bit further from the eyes and lower in the field of vision will reduce the amount of muscle contraction needed. Periodically focusing on more distant objects will help relax those muscles. For people working at a computer workstation, it is usually possible to arrange the computer display 3+ feet away from the eyes, and in the bottom half of the field of view. Periodically looking away from the display while thinking and remembering to get up and stretch/walk around every once in a while can make a big difference for anyone experiencing eye strain.