- abnormally high fluid pressure in the eye, most commonly caused either by blockage of the channel through which aqueous humor drains (open-angle glaucoma, or chronic glaucoma ) or by pressure of the iris against the lens, which traps the aqueous humor (angle-closure glaucoma, or acute glaucoma ).
- a disease of the eye in which pressure within the eyeball damages the optic disc, impairing vision, sometimes progressing to blindness
