Glaucoma: the silent thief of sight and how to catch it early
Glaucoma often has no early symptoms. Learn who is at risk, how glaucoma is diagnosed and treated, and why regular eye checks after 40 matter.
Glaucoma is a group of eye conditions that damage the optic nerve, the cable that carries images from the eye to the brain. Lost vision from glaucoma cannot be restored, yet most people feel nothing until the disease is advanced. Early detection makes the biggest difference.
What is glaucoma?
Open-angle glaucoma
In the most common type, open-angle glaucoma, the optic nerve is damaged slowly over years. Side vision is affected first, so it goes unnoticed while central vision stays sharp.
Angle-closure glaucoma
Angle-closure glaucoma happens when the drainage angle inside the eye narrows or closes. An acute attack can cause sudden eye pain, headache, blurred vision, haloes around lights and nausea. This is an emergency and needs care the same day.
Who is at risk?
Common risk factors
Risk rises with age, especially after 40. A family history of glaucoma, high eye pressure, high short-sightedness or long-sightedness, diabetes, long-term steroid use and a past eye injury all increase the risk. People of Asian descent have a higher rate of angle-closure glaucoma.
How glaucoma is diagnosed
The eye examination
A glaucoma check includes measuring eye pressure, examining the optic nerve, and looking at the drainage angle. A normal eye pressure alone does not rule glaucoma out.
Tests that track change
A visual field test maps your side vision, and an optical coherence tomography (OCT) scan measures the nerve fibre layer. Repeating these tests over time shows whether the condition is stable.
Treatment options
Eye drops
Treatment aims to lower eye pressure to protect the optic nerve. Daily eye drops are often the first step and work best when used every day as prescribed.
Laser and surgery
Laser treatment can improve drainage or open a narrow angle. When drops and laser are not enough, surgery creates a new drainage route. Your doctor will explain which option suits your type of glaucoma.
Frequently asked questions
Can glaucoma be cured?
Glaucoma cannot be cured and lost vision cannot be restored, but treatment can slow or stop further damage in most people.
How often should I have a glaucoma check?
Adults over 40 should have a full eye examination every one to two years, or more often if they have risk factors. Your doctor will advise you.
Is glaucoma hereditary?
A family history raises your risk. If a parent, brother or sister has glaucoma, tell your eye doctor and have regular checks.
Medically reviewed by
Dr. Then Kong Yong
Consultant Ophthalmologist · ISEC KL · reviewed 30 Oct 2026
This article is general information and does not replace a consultation. Every eye is different: please see an eye doctor about your own symptoms and treatment.
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