Closed-angle glaucoma is an eye disorder in which the colored part of the eye (iris) and the lens block the movement of fluid between the chambers of the eye.

The blockage of fluid causes pressure to build up in the eye and causes the iris to press on the drainage system (trabecular meshwork) of the eye. The increased pressure can cause damage to the optic nerve, leading to vision loss and possible blindness.

Closed-angle glaucoma may cause sudden blurred vision with pain and redness, usually in one eye first. It can be an emergency situation (acute closed-angle glaucoma) that needs immediate medical care to prevent permanent damage to the affected eye. Treatment may include medications to lower the pressure in the eye (intraocular pressure, or IOP), monitoring of the drainage angle, and possibly surgery. The opposite eye is also usually examined and eventually treated because the condition is likely to affect the other eye as well.