What are the Symptoms of Glaucoma?

Brunette woman making an eye test in a surgery

Glaucoma is often called the “silent thief of sight” because it has no discernable symptoms until the disease has already progressed. That’s why it’s so important to have regular eye exams. However, you should also know there’s an acute form of glaucoma with sudden symptoms that should be treated immediately.

Brunette woman making an eye test in a surgeryWe’ll discuss both types of glaucoma in today’s blog. First, let’s talk about what glaucoma is, so you can be fully informed when you talk to your eye doctor.

What is Glaucoma?

When the fluid in your eye (called aqueous humor) doesn’t drain properly, it can build up and cause damaging pressure to your optic nerve. This is a nerve at the back of your eye that connects to your brain. The optic nerve sends light signals to your brain, so you can see. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. Over time, central (straight-ahead) vision may decrease until no vision remains.

Since fluid build-up is the primary problem, monitoring eye pressure is important. During an eye exam, your eye doctor will measure your eye’s fluid pressure (called intraocular pressure). Eye pressure is unique to each person, so it’s not the only indicator for glaucoma. It’s simply another piece of information to help your eye doctor assess your eyes. The range for normal pressure is 12-22 mm Hg (millimeters of mercury, a scale for recording eye pressure). Most glaucoma cases are diagnosed with pressure over 20mm Hg.

Your eye doctor will also examine your optic nerve. With your eyes dilated, your optic nerve is magnified using a small device with a light on the end. Based on the results of these tests, your doctor may ask you to have more glaucoma exams to confirm a diagnosis.

Glaucoma Symptoms

Since the two primary forms of glaucoma have radically different symptoms, we’ll address each one individually.

Open Angle Glaucoma

This is the most common form of glaucoma, affecting about four million Americans. There are typically no early warning signs or symptoms. It develops slowly and often without noticeable sight loss for many years. The first signs for this type of glaucoma are diminishing peripheral vision.

In open angle glaucoma, the eye’s drainage canals become clogged over time, causing a gradual increase in internal eye pressure and damage to the optic nerve. Due to its lack of symptoms, regular eye exams are critical. If glaucoma is detected early, your eye doctor can prescribe a preventative treatment to help protect your vision.

Angle Closure Glaucoma

In contrast to open angle glaucoma, symptoms of acute closure glaucoma are very noticeable, and damage occurs quickly. You may experience:

  • Hazy or blurred vision
  • Rainbow-colored circles around bright lights
  • Severe eye and head pain
  • Nausea or vomiting (with severe eye pain)
  • Sudden sight loss

In angle closure glaucoma, the drainage system of the eye becomes blocked. Depending on the severity of the blockage, the rise in eye pressure may occur suddenly or gradually. If you experience any of these symptoms, you should see an eye doctor immediately.

Although glaucoma is not curable, it’s very manageable with the right treatment. Since the most common form of glaucoma doesn’t have symptoms until its later stages, regular eye exams are the best defense against glaucoma.