Glaucoma: Types, Symptoms, Causes & Diagnosis

by Ishani Bose last updated -

 Likes  Comments

Glaucoma is a very common condition that affects the eye and is one of the leading causes of blindness. It can affect anyone, particularly those above the age of 55 years. The condition can develop gradually, without any obvious symptoms or pain, making it difficult to diagnose. This condition is one of the main reasons why a visit to an optometrist is recommended at least once a year. Most people suffer from glaucoma in both eyes, causing a general decrease in a person’s vision, not partial impairment. However, it is also possible for one to experience this discomfort only in one eye.

What is Glaucoma?

According to MedlinePlus, Glaucoma is a group of diseases that cause a rise in its fluid pressure, commonly known as intraocular pressure, further damaging the eye’s optic nerve. The nerve ceases to transmit messages to the brain properly due to this excessive pressure. If glaucoma isn’t addressed in time, the problem will only get worse, eventually leading to a complete loss of vision. However, before making changes to your lifestyle to lower your risk of glaucoma, it is essential to understand the details of this condition, as well as the types.


Johns Hopkins Medicine states that there are two main types, apart from the other rare varieties, including primary open-angle, closed-angle, congenital and normal-tension glaucoma.

Open-angle Glaucoma

This variety of glaucoma is the most common (representing more than 90% of all cases). According to a review by Dr. M. Cristina Leske this form is characterized by the gradual clogging or blockage of the drainage channels in the eye. Unlike the second main variety of this condition, the angle between the iris and cornea is open normally. This type of glaucoma, also known as primary glaucoma, may take years or decades before the symptoms begin to manifest.

Closed-angle Glaucoma

This is considered a medical emergency that requires immediate attention. It occurs when the drainage channels are blocked suddenly, resulting in a rapid rise in intraocular pressure, making it impossible to ignore. The speed at which this condition develops is due to the closed angle between the iris and cornea, making it much more difficult for any fluid to be redirected.

Congenital Glaucoma

An extremely rare condition that affects a prenatal infant, it is characterized by the improper formation or development of the drainage channels. If possible, this condition can be quickly remedied with microsurgery before further growth and development occur.

Normal-Tension Glaucoma

This is a mysterious variant in which the optic nerve begins to show damage, despite not being under pressure from the aqueous humor fluid. Experts have yet to explain the root cause of this condition, although the symptoms are quite like primary glaucoma.


The most common symptoms include the following:

  • Blind spots
  • Blurred vision
  • Redness in the eye
  • Headaches
  • Nausea
  • Forehead pain

However, different types of glaucoma have different symptoms:

In open-angle glaucoma, symptoms may not appear until the damage has already been done to the optic nerve. The condition will begin with sporadic blind spots in the peripheral vision, which may not immediately be apparent. However, the spots will continue to spread and worsen, and the loss of vision can come quickly after these spots develop.

In closed-angle glaucoma, the symptoms are not constant, instead, they happen very rapidly following a sudden rise in intraocular pressure. At the beginning of an “attack”, you may experience a painful headache, in addition to blurred vision and halos around lights or other objects. The discomfort will increase rapidly and can cause severe pain in the forehead and eyes followed by nausea, and vomiting. If you experience these symptoms, see your ophthalmologist immediately, as this is generally considered as a medical emergency.


According to the American Academy of Opthalmology, the most common causes include the following:

Excess intraocular pressure

Glaucoma occurs due to the build-up of excess fluid in the front part of the eye. This fluid is called the aqueous humor and fills the anterior and posterior chambers of the eye; its main purpose is to provide nutrients like amino acids to various parts of the eye, in addition to keeping the eye inflated. The intraocular pressure is maintained by this fluid, but if the fluid doesn’t exit the eye, that pressure can increase. As the aqueous humor circulates, it leaves the eye through a mesh-like filter or screen. If this channel is blocked for any reason, the liquid will continue to build up, resulting in the symptoms of glaucoma.

Eye-related problems

Acute injuries to the eye, eye infections, and inflammation in the eye can also cause these channels to become blocked.


This health condition also appears to run in families, so there is a genetic component to this channel becoming obstructed.

If you or your loved ones are experiencing any of the aforementioned symptoms, it would be advisable that you consult your medical supervisor immediately. Protection Status
About the Author

An alumnus of St. Xavier’s College, Mumbai, Ishani Bose has worked as a reporter/features writer for several leading newspapers and organizations in India. It was her love for food, health, and wellness that brought her to Organic Facts. As a Content & Culinary Outreach Specialist, she is responsible for developing and managing the website’s recipe section. An avid Instagrammer who knows the latest social media trends, Ishani helps strategize and create authentic content for the website’s social media platforms. When not writing or cooking, you’ll find her reading, traveling, soaking herself in music, arts, and culture in every way possible. Ishani is currently pursuing an online program on “Introduction to Food and Health” by Stanford University, US. 

Rate this article
Average rating 2.5 out of 5.0 based on 2 user(s).