The most common types of glaucoma — primary open-angle glaucoma and acute angle-closure glaucoma — have completely different symptoms.

Primary open-angle glaucoma signs and symptoms include:

• Gradual loss of peripheral vision, usually in both eyes
• Tunnel vision in the advanced stages

Acute angle-closure glaucoma signs and symptoms include:

• Severe eye pain
• Nausea and vomiting (accompanying the severe eye pain)
• Sudden onset of visual disturbance, often in low light
• Blurred vision
• Halos around lights
• Reddening of the eye

Both open-angle and angle-closure glaucoma can be primary or secondary conditions. They're called primary when the cause is unknown and secondary when the condition can be traced to a known cause, such as eye injury, inflammation, tumor, advanced cataract or diabetes. In secondary glaucoma, the signs and symptoms can include those of the primary condition as well as typical glaucoma symptoms.

Risk factors

Because chronic forms of glaucoma can destroy vision before any signs or symptoms are apparent, be aware of these factors:

• Elevated internal eye pressure (intraocular pressure). If your intraocular pressure is higher than normal, you're at increased risk of developing glaucoma, though not everyone with elevated intraocular pressure develops the disease.
• Age. Everyone older than 60 is at increased risk of glaucoma. For certain population groups such as African-Americans, however, the risk is much higher and occurs at a younger age than that of the average population. If you're African-American, ask your doctor when you should start having regular comprehensive eye exams.
• Ethnic background. African-Americans are five times more likely to get glaucoma than are Caucasians, and they're much more likely to experience permanent blindness as a result. Mexican-Americans and Asian-Americans also face an increased risk.
• Family history of glaucoma. If you have a family history of glaucoma, you have a much greater risk of developing it. Glaucoma may have a genetic link, meaning there's a defect in one or more genes that may cause certain individuals to be unusually susceptible to the disease. A form of juvenile open-angle glaucoma has been clearly linked to genetic abnormalities.
• Medical conditions. Diabetes and hypothyroidism increase your risk of developing glaucoma.
• Other eye conditions. Severe eye injuries can result in increased eye pressure. Injury can also dislocate the lens, closing the drainage angle. Other risk factors include retinal detachment, eye tumors and eye inflammations, such as chronic uveitis and iritis. Certain types of eye surgery also may trigger secondary glaucoma.
• Nearsightedness. Being nearsighted, which generally means that objects in the distance look fuzzy without glasses or contacts, increases the risk of developing glaucoma.
• Prolonged corticosteroid use. Using corticosteroids for prolonged periods of time appears to put you at risk of getting secondary glaucoma. This is especially true if you use corticosteroids eyedrops.

Eyedrops

Glaucoma treatment often starts with medicated eyedrops. Be sure to use the drops exactly as prescribed. Otherwise, your optic nerve damage could get even worse. If your doctor prescribes more than one type of eyedrop, make sure to ask how long to wait between applications. Because some of the eyedrops are absorbed into your bloodstream, you may experience side effects unrelated to your eyes. To minimize this absorption, close your eyes for one to two minutes after putting the drops in. Press lightly at the corner of your eye near your nose to close the tear duct for one or two minutes, and wipe off any unused drops from your eyelid.