Glaucoma is a chronic, progressive, degenerative disorder of the optic nerve that produces characteristic visual field damage. Glaucoma is the second cause of blindness, and importantly: it is irreversible.

It is estimated that around 80 million people have glaucoma worldwide. Approximately 50% of the individuals with glaucoma are unaware that they have the disease, and this number may be even higher in underdeveloped countries. This is because in its early stages, glaucoma is asymptomatic. If untreated, glaucoma may progress to blindness.

Periodic testing allows early diagnosis to prevent visual disability.