It's important to keep in mind that most people with open-angle glaucoma, the most common type, have no symptoms until they have lost a significant amount of vision.
The condition can be prevented, but once vision is lost, it is irreversible. That is why it's very important to get regular exams with an eye doctor, particularly if there is a family history of glaucoma.
Loss of peripheral field vision may be the first symptom of glaucoma, and because this happens so gradually, the individual usually does not notice the loss of sight.
Acute Closed- or Narrow-Angle Glaucoma
Symptoms of acute closed- or narrow-angle glaucoma include sudden onset of severe throbbing pain and redness in the eye, headaches (on the same side as the affected eye), blurred vision, halos around lights, foggy vision, a dilated pupil, and sometimes nausea and vomiting. It is often described as “the worst eye pain of my life”.
This type of glaucoma is a medical emergency and should be treated immediately. Damage to the optic nerve may begin within a few hours and, if not treated within six to twelve hours, it may result in severe permanent loss of vision or blindness and even a permanently enlarged (dilated) pupil
Congenital Glaucoma in Infants
Symptoms of congenital glaucoma, sometimes seen in newborns or in the first few years of life, include:
Tearing, sensitivity to light, and eyelid spasm
A larger cornea and clouding of the normally transparent cornea
Habitual rubbing of the eyes, squinting, or keeping the eyes closed closed much of the time
Secondary and Other Forms of Glaucoma
Symptoms will depend on the underlying condition contributing to the abnormal rise in eye pressure. Inflammation inside the eye (uveitis) frequently causes halos and light sensitivity. Injured eyes may mask glaucoma symptoms if eye damage (corneal edema, bleeding, or retinal detachment, for example) is already present. If a cataract is the cause, vision will have been markedly decreased for a long time. Doctors managing such complicated eye conditions monitor the intraocular pressure, the eye's internal drain, the appearance of the optic nerve, and visual fields, in order to detect the earliest signs of glaucoma.