Acute narrow angle glaucoma occurs primarily in patients who have a shallow space between the cornea at the front of the eye and the colored iris that lies just behind the cornea. As the eye ages, the natural lens behind the pupil grows and the pupil becomes smaller, restricting the flow of fluid to the drainage site. Fluid can build up behind the iris, pushing it forward and blocking the channel (angle) that normally allows aqueous fluid to drain. If blockage happens, a rapid rise in intraocular pressure can occur. Pupillary block.  Eye fluid known as the aqueous humor is produced in the ciliary body, which is located behind the iris. Normally, the aqueous flows easily through the pupil into the front or anterior chamber of the eye. But if the back...

Glaucoma is often called "the sneak thief of sight." This is because, in most cases of glaucoma the intraocular pressure of the eye can build up and destroy sight without causing obvious symptoms. Acute narrow angle glaucoma (also called angle closure glaucoma) is one of the two basic categories of glaucoma. The other category is open angle glaucoma. There are anatomical factors in the eye which will cause a narrow or smaller space between the peripheral iris and trabecular meshwork. This happens when the drainage canals get blocked or covered over. The iris gets pushed against the lens of the eye, shutting off the drainage angle. Sometimes the lens and the iris stick to each other. This results in pressure increasing suddenly, usually in one eye. There may be a feeling of...