Traumatic changes in the iridocorneal angle, e.g. in ball sports, can lead to secondary glaucoma. High intensity resistance exercise or yoga exercises - such as the headstand - can increase IOP, and deterioration in the visual field and acute narrow angle glaucoma attacks have been described in some case reports. Glaucoma therapy of professional athletes with steroids, carbonic anhydrase inhibitors and beta-blockers can result in positive doping tests. In manifest glaucoma, moderate aerobic exercise is presumably of use because of the IOP lowering effect, improved retinal perfusion and reduction in oxidative stress.