Glaucoma: symptoms, eye tests, treatment and who is at risk
What glaucoma is, why it steals sight silently, who should be checked, the tests that find it, and how drops, laser and surgery protect your vision.
What glaucoma is
Glaucoma is a group of eye conditions that damage the optic nerve, the cable that carries signals from the eye to the brain. It is often, but not always, linked to raised pressure inside the eye. Damage usually starts at the edges of vision and slowly moves inwards. Vision lost to glaucoma cannot be restored, but treatment can slow or stop further loss — which is why finding it early matters so much.
There are two main kinds. In open-angle glaucoma, the drainage channels of the eye work less well over years and pressure rises slowly, without symptoms. In angle-closure glaucoma, the drainage angle is narrow and can become blocked; this can happen gradually, or suddenly as an emergency. Angle-closure glaucoma is relatively common in Asian populations. Glaucoma can also follow eye injury, long-term steroid use or other eye diseases, and can be present in babies.
Symptoms
Open-angle glaucoma usually has no symptoms until a lot of vision has been lost. When symptoms appear, they include:
- Loss of side vision, bumping into things or missing steps
- Tunnel vision in late stages
Acute angle-closure glaucoma comes on suddenly and is an emergency:
- Severe eye pain and headache
- A red eye
- Blurred vision
- Halos around lights
- Nausea and vomiting
Some people with narrow angles have brief, milder attacks of blurring, halos or aching, often in the evening or in dim light, which settle on their own. These are a warning and need an eye examination.
Who is at risk
- Age over forty, with risk rising further with age
- A parent, brother or sister with glaucoma — family members should be checked regularly
- High eye pressure found at an eye test
- Long-sightedness, which is linked to narrow angles
- Short-sightedness, which is linked to open-angle glaucoma
- Diabetes, high blood pressure or very low blood pressure
- Long-term use of steroid eye drops, inhalers, creams or tablets — never use steroid eye drops without an eye doctor's supervision
- A past eye injury
How it is diagnosed
Glaucoma cannot be detected with a simple vision test. A full eye examination usually includes:
- Tonometry — measures the pressure inside the eye
- Dilated eye examination — the doctor examines the optic nerve for the typical 'cupping' of glaucoma
- Visual field test — maps your side vision by asking you to press a button when you see lights
- Gonioscopy — a special lens on the eye shows whether the drainage angle is open or narrow
- OCT scan — a quick, painless scan that measures the nerve fibre layer and detects early damage
These tests are repeated over time to see whether the disease is stable. A single high pressure reading does not mean you have glaucoma, and normal pressure does not rule it out.
Which doctor to see
Glaucoma is diagnosed and treated by an ophthalmologist, and complex cases by a glaucoma specialist. Optometrists can pick up warning signs and refer you. Under India's National Programme for Control of Blindness and Visual Impairment, diagnosis and treatment of glaucoma and other eye diseases are offered at district hospitals and identified NGO eye hospitals.
You can find ophthalmologists in Bengaluru on The Doctor Index, each with a registration you can check.
Treatment
All treatment aims to lower eye pressure to a level that protects the optic nerve. Your doctor will set a target pressure for you and adjust treatment based on your tests.
- Eye drops — the usual first treatment. Several classes reduce the fluid the eye makes or help it drain. They must be used every day, for life, even though you feel no difference.
- Laser treatment — for open-angle glaucoma, a laser can improve drainage and may reduce or replace drops. For narrow angles, a laser makes a tiny hole in the iris (laser iridotomy) to prevent an attack; it is often done in both eyes.
- Glaucoma surgery — operations or small drainage devices that create a new path for fluid to leave the eye, used when drops and laser are not enough. Cataract surgery can also help some people with angle-closure glaucoma.
Learn how to put in drops correctly: one drop is enough, close the eye gently and press on the inner corner for a minute. Tell your doctor about side effects such as redness, stinging or breathlessness, rather than stopping the drops on your own.
Living with glaucoma
- Use your drops at the same times every day; a phone reminder helps
- Keep every follow-up visit and repeat test, usually every few months
- Tell every doctor that you have glaucoma, as some medicines can trigger angle closure
- Ask your brothers, sisters and children to have eye checks
- Stay active; regular exercise is good for general and eye health
If your side vision has been affected, ask whether it is safe for you to drive, and take extra care on stairs and in poor light. Low-vision aids and rehabilitation services can help people with advanced glaucoma stay independent.
When it is an emergency
Sudden severe eye pain with redness, blurred vision, halos, headache and vomiting may be acute angle-closure glaucoma, which can cause permanent loss of sight within hours. Go to an eye hospital or emergency department immediately — call 112 or 108 if you cannot get there quickly. Also seek urgent care for sudden loss of vision in either eye.
Questions to ask at your appointment
- What type of glaucoma do I have, and how advanced is it?
- What is my target eye pressure?
- How do I use my drops correctly, and what side effects should I watch for?
- Would laser or surgery help me?
- How often do I need tests?
- Should my family be checked?
Common questions
Questions people ask
- Can glaucoma be cured?
- No, but it can usually be controlled. Vision already lost cannot be restored, but lowering eye pressure with drops, laser or surgery slows or stops further damage in most people. Using treatment every day and attending check-ups are key.
- I can see well. Do I still need a glaucoma check?
- Yes, if you are over forty, have a family history, diabetes, or use steroids. Open-angle glaucoma causes no symptoms and central vision stays good until late. Only an eye examination with pressure and optic nerve checks can find it early.
- Do I have to use glaucoma drops for life?
- Usually yes, unless laser or surgery controls the pressure well enough to stop them. Glaucoma is a long-term condition, and stopping drops lets pressure rise again silently. Never stop or change your drops without talking to your eye doctor.
- Can steroid eye drops cause glaucoma?
- Yes. In some people, steroid eye drops, and steroids in other forms, raise eye pressure and can cause glaucoma and cataract. This is why steroid eye drops should be used only when prescribed by an eye doctor, with pressure checks.
This condition is usually assessed by an ophthalmologist. Every profile shows the doctor’s registration and what has been checked.
Ophthalmologists in Bangalore
A few ophthalmologists listed on The Doctor Index. They are shown because of their speciality, not a stated interest in Glaucoma; ask the clinic whether the doctor sees it.
Related conditions
All ophthalmology conditions →
Practical reading
All postsSources
- MedlinePlus, US National Library of Medicine — Glaucoma
- Glaucoma Research Foundation — Types of glaucoma
- Ministry of Health and Family Welfare — National Programme for Control of Blindness and Visual Impairment
- MedlinePlus, National Library of Medicine — Glaucoma — Public-domain health-topic summary
Glaucoma: symptoms, eye tests, treatment and who is at risk is original text by The Doctor Index; the compiled source draft was used for research. Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.
General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-1013.