Glaucoma is the second largest cause of blindness globally and the main cause of irreversible blindness. It is caused by an increase in intraocular pressure, which causes gradual damage to the optic nerve that conveys visual impulses to the brain – any damage to the optic nerve results in vision loss. 

Usually, the ailment progresses slowly and insidiously, and the individual is generally unaware of the condition until it is too late. When one experiences a symptom, there is generally already moderate to severe nerve damage. This is why the condition is known as the “quiet thief of sight”.

Loss of vision from glaucoma

Different Types of Glaucoma

Glaucoma usually progress slowly, with the most prevalent kinds being Primary Open-Angle Glaucoma and Chronic Angle-Closure Glaucoma. These commonly afflict those in their 40s or 50s. Glaucoma can be inherited, which means that relatives of glaucoma patients are at a higher risk.

Primary Open-Angle Glaucoma

In many countries, Primary Open-Angle Glaucoma is the most commonly found. It progresses slowly and has hardly any symptoms in the early stages.

Chronic Angle-Closure Glaucoma

Asians are prone to having angle-closure glaucoma, with Singapore having the world’s highest documented incidence of it. In chronic form, this type of glaucoma develops gradually, similar to Primary Open-Angle Glaucoma, and often goes unrecognised for a long time. It is caused by increasing obstruction of the eyeball’s drainage pathways, resulting in a prolonged rise in eye pressure.

Acute Angle Closure Glaucoma

This kind of glaucoma typically affects middle-aged or older women. It is caused by a blockage of the fluid drainage pathway in the angle of the eye. This results in a fast rise in fluid pressure within the eye. The symptoms are sudden and dramatic, and requires the individual to seek immediate medical intervention.

Secondary Glaucoma

Glaucoma can also develop when the eyeball gets inflamed or when a cataract becomes too advanced and large. Other causes of secondary glaucoma are having undergone eye surgery or an eye injury.


Symptoms of Glaucoma

Because peripheral vision is impaired first and the disease progresses slowly, people with Primary Open-Angle Glaucoma and Chronic Angle-Closure Glaucoma frequently have no symptoms in the early stages. Most people do not realise they have glaucoma until their central vision begins to deteriorate. By then, there may have already been considerable permanent nerve damage.

On the other hand, Acute Angle-Closure Glaucoma causes significant eye pain, redness, blurring, and the appearance of haloes around lights. When this happens, the individual should seek immediate medical attention.


Risk Factors

Be aware of the following glaucoma risk factors:

  • Over 60 years old
  • A family history of glaucoma
  • Diabetes and excessive blood pressure
  • Excessively high or low short- or long-sightedness.
  • A history of eye injuries or certain types of eye surgeries

Pay close attention to your eye health and have regular comprehensive eye exams as recommended by your eye doctor to lower your chances of developing chronic glaucoma.


Glaucoma develops gradually and gets harmful eventually. During the early stages of the disease, most have only minor symptoms; they are only aware of the illness in its advanced stages. Glaucoma eye screening is extremely beneficial in detecting the condition early and initiating the best possible available treatment.