Glaucoma is the most common cause of blindness in older adults. The condition involves damage to the eye’s optic nerve, and without treatment, it can lead to vision loss or blindness.

Glaucoma is a condition that results from pressure buildup within the eye, which can damage the optic nerve and lead to vision problems, including blindness.

According to the Centers for Disease Control and Prevention (CDC), around 3 million people in the United States have glaucoma.

Read on to learn more about glaucoma and blindness, including how to prevent blindness and possible treatments.

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The main cause of glaucoma is a buildup of pressure inside the eye. This pressure can cause damage to the optic nerve. The optic nerve sends visual signals to a person’s brain, allowing them to see.

A transparent layer called the cornea covers the eye’s pupil and iris. The anterior chamber between the iris and cornea contains fluid known as aqueous humor.

Aqueous humor nourishes the eye and helps it maintain its shape. As fluid fills the eye, the same amount leaves the area via the drainage angle, which helps maintain pressure.

If there is a problem with a person’s drainage angle, fluid can build up in the eye. This increases pressure in the eye, which can damage the optic nerve.

The optic nerve consists of over a million tiny nerve fibers. Damage to these fibers can cause blind spots in a person’s vision. Damage to all these fibers causes blindness.

According to the CDC, glaucoma is the second leading cause of blindness in the world. Additionally, it is the leading cause of blindness in people over age 60 years.

Glaucoma accounts for 9–12% of all cases of blindness in the U.S.

Open-angle glaucoma

The two main types of glaucoma are open-angle glaucoma and angle-closure glaucoma.

Over 90% of people with glaucoma have open-angle glaucoma.

Open-angle glaucoma occurs when aqueous humor does not drain correctly from a person’s eye. Over time, pressure builds in the eye, causing damage to the optic nerve.

Open-angle glaucoma develops gradually and may cause no immediate symptoms. A person may not know they have open-angle glaucoma until they have symptoms.

Without treatment, open-angle glaucoma can lead to blindness.

Angle-closure glaucoma

Angle-closure glaucoma occurs when the drainage angle is too narrow, making it difficult for fluid to drain properly from the eye.

A person can have a narrow drainage angle for a long time without symptoms. However, if the angle closes completely (acute angle-closure glaucoma), the eye pressure can rise rapidly, causing vision loss within hours or days.

This is an emergency that requires immediate medical attention. Without prompt treatment, a person may go blind.

Certain risk factors can increase a person’s chances of developing glaucoma, including:

  • being over 40 years old
  • being of African, Asian, or Hispanic heritage
  • having high eye pressure
  • being farsighted or nearsighted
  • having had a previous eye injury
  • using steroid medications long term
  • having corneas that are thin in the center
  • having an optic nerve that is thinning
  • having a family history of glaucoma
  • having diabetes, migraine, high blood pressure, or poor circulation

The CDC recommends the following to prevent blindness from glaucoma:

  • getting regular eye exams
  • getting a comprehensive dilated eye exam if the person is at high risk of glaucoma
  • getting a comprehensive dilated eye exam by the age of 40 years old
  • controlling blood pressure
  • being physically active
  • avoiding smoking cigarettes
  • using prescription eye drops to prevent the condition from progressing

There is currently no cure for glaucoma. Vision loss as a result of glaucoma is permanent and not reversible.

However, certain treatments can prevent further damage to the eye. These treatments include:

  • medicated eye drops
  • laser surgery to drain fluid from the eye
  • trabeculectomy, a form of surgery that allows fluid to drain into a pocket in the eye
  • glaucoma drainage devices
  • cataract surgery to remove the eye lens, which leaves more space for fluid to leave the eye

In addition to blindness, glaucoma can cause:

  • blind spots
  • peripheral vision loss
  • difficulty adjusting to changes in light
  • trouble seeing obstacles

With angle-closure glaucoma, if the drainage angle becomes blocked completely, it can cause acute angle-closure glaucoma. A person should seek immediate medical attention if they notice any of the following symptoms:

  • sudden blurred vision
  • severe eye pain
  • eye redness
  • decreased vision
  • headache
  • nausea
  • vomiting
  • rainbow-colored rings or halos around lights

Below are some frequently asked questions about glaucoma.

How long does it take for glaucoma to cause blindness?

It can take years for glaucoma to cause blindness. Early diagnosis is key for helping prevent the progression of the condition.

If a person has an acute angle-closure glaucoma attack and does not seek medical attention, they can quickly go blind.

What percentage of glaucoma patients go blind?

According to the Glaucoma Research Foundation, a person has a 5% chance of becoming legally blind due to glaucoma.

Will I go blind if I get glaucoma?

No, not every case of glaucoma results in blindness. Receiving early treatment can help prevent loss of sight due to glaucoma.

What helps glaucoma go away?

There is no cure for glaucoma. An ophthalmologist can treat a person’s glaucoma to help prevent it from progressing.

Glaucoma is a group of conditions that affects a person’s optic nerve. Without treatment, glaucoma can cause blindness.

Although there is no cure for glaucoma, treatment can help prevent the condition from progressing.

A person should speak with their doctor if they have any signs of glaucoma. A person experiencing symptoms of an acute angle-closure glaucoma attack should seek immediate medical attention.