Open-angle glaucoma has few signs in its early stages; however, patients gradually lose peripheral vision, according to the Glaucoma Research Foundation. Angle-closure glaucoma sets in quickly, and patients experience hazy vision, sudden loss of vision and severe pain in the head and eyes.They also see rainbow-colored halos around lights.
Patients should see a doctor immediately if they begin to experience symptoms of angle-closure glaucoma because the damage the disease causes can be quick and devastating, reports the Glaucoma Research Foundation. Seeing an eye doctor regularly can help to catch open-angle glaucoma in its early stages, but the progression of this form of the disease is usually very slow.
The two forms of the disease progress differently because of their causes. Open-angle glaucoma occurs because drainage canals in the eye become blocked over time, according to the Glaucoma Research Foundation. This leads to a gradual rise in pressure in the eye. On the other hand, angle-closure glaucoma occurs because of a sudden blockage in the eye's drainage canals. This causes a rapid rise of pressure in the eye. A person may be at risk for glaucoma if he is over age 40, has had trauma to the eyes, or takes certain medications, according to WebMD.