Why are your eyes so tired at the end of a long workday? You are actually exercising what ophthalmologist James P. McCulley of the University of Texas Medical School calls “among the most active muscles in the body.”
1. Computer work and reading requires more muscles.
Your eyes contain three sets of muscle groups. Concentrated reading or close work provides a workout for these muscle groups strenuous enough to make Richard Simmons proud. Unfortunately, as in all aerobic programs, the saying “no pain, no gain” applies, as Winnipeg, Manitoba, optometrist Steven Mintz explains:
The human eye is designed so that, if perfectly formed, it will form a clear image on the retina (at the back of the eye) of any distant object without having to use any of the muscles. In order to see closer objects clearly, however, each set of muscles has to work. The extraocular muscles must turn each eye inward; the sphincter muscles must work to make the pupil smaller; and the ciliary muscles must contract to allow the lens to change to a shape that will produce a clearer image.
Solution: Focus on a distant object to immediately feel your eyes relax.
2. Your eyes are imperfect.
This minimal muscular effort is significant in itself. However, no human eye is perfectly formed and these imperfections will increase the amount of effort required. For instance, people who are farsighted must exert more than the normal amount of effort on the part of the ciliary muscles. Many people have extraocular muscle imbalances that force them to work harder. Virtually every person, as [he or she] approaches or passes the age of forty, suffers from a stiffening of the lens inside the eye, which forces those ciliary muscles to work even harder.
