That is an excellent question. Unfortunately, the data on this subject is not consistent throughout the literature. There are multiple randomized studies currently looking at the effect of exercise on intraocular pressure. What we are finding is that it may depend on the type of exercise, the overall fitness of the patient, or other factors that we do not yet understand.

In general, eye pressure can be transiently increased by any exercise or activity that induces a “Valsalva.” The Valsalva maneuver, as defined by Wikipedia, "is performed by forcible exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut. Variations of the maneuver can be used either in medical examination as a test of cardiac function and autonomic nervous control of the heart, or to "clear" the ears and sinuses (that is, to equalize pressure between them) when ambient pressure changes, as in diving or aviation." Holding your breath and bearing down to pick up a heavy object (heavy weight lifting) or even playing an instrument, such as the trumpet, are both methods of causing a Valsalva maneuver as well, and can transiently increase eye pressure. In addition, there is some evidence that certain yoga positions may also increase pressure inside the eye. Inverted positions that place the eyes below the heart for an extended period of time have the greatest potential for increasing the pressure inside the eye.

While some studies have shown an association with increased intraocular pressure and exercise, there are new studies showing that aerobic exercise may actually decrease intraocular pressure transiently. Overall, I do not believe that studies on exercise and intraocular pressure are consistent enough to draw many conclusions or provide a definitive recommendation. In general, as physicians, we would all recommend our patients follow an exercise regiment for your general health. Avoiding prolonged heavy weight lifting or inverted yoga positions may be reasonable until we have definitive studies to examine their long term effects. I encourage you to consult with your eye doctor and your primary care doctor to determine an appropriate exercise regiment for you.