This is the most common type, and tends to be hereditary. Increased eye pressure causes slow, progressive damage; it shows no symptoms in most cases, and the patient notices vision loss only once the damage is already advanced.

This presents acutely: eye pressure rises rapidly. Symptoms include intense eye pain, blurred or limited vision, rainbow-like halos around lights, redness and a feeling of swelling in the eye, nausea and vomiting.

This occurs secondary to conditions such as diabetes or uveitis, eye injuries, corticosteroids, certain types of cataracts and others. Its symptoms can resemble either open-angle or angle-closure glaucoma, since they relate to the underlying cause.

This results from arrested development of the eye's drainage angle. The most common symptoms are corneal cloudiness, enlargement and/or redness of the eye, light sensitivity and tearing. It is classified differently depending on when it appears and the eye's characteristics.