The short version
Glaucoma damages the main nerve that connects the eye to the brain. It usually develops slowly, over many years.
There is no cure. But the NHS says that treatments can slow down the damage and help stop your vision getting worse. For many people, treatment means eye drops every day and regular eye clinic appointments.
The NHS says it is normal to worry about your vision. It also says that if glaucoma is found and treated early, it may not change your vision much.
What glaucoma is
The NHS says glaucoma is usually caused by a build-up of pressure in the eye. This happens when the fluid in the eye cannot drain as it should. The pressure damages the optic nerve, which connects the eye to the brain. Sometimes the pressure is in the normal range, but the nerve is still damaged.
Glaucoma does not usually have symptoms at first, so most people do not realise they have it. It is usually found during a routine eye test. It usually affects both eyes, but it may be worse in one eye.
The National Eye Institute says vision loss usually starts with side vision, especially the part closest to the nose. MedlinePlus says the amount of pressure the optic nerve can handle is different for each person.
Source: NHS · US National Eye Institute · MedlinePlus (US National Library of Medicine)
What happens next
The NHS says that if you are told you have glaucoma, you should be referred to a specialist eye doctor (an ophthalmologist) for further tests. Your treatment depends on how your sight is affected and on the type of glaucoma you have. Your specialist will advise you on how glaucoma may affect your sight.
Tests you may have
The National Eye Institute says the eye exam is simple and painless. MedlinePlus describes these parts of it:
- A dilated eye exam. Drops widen your pupils. Then the eye doctor looks at the back of the eye, including the optic nerve, through a special magnifying lens.
- A visual field test. This checks how well you see things off to the side, without moving your eyes.
- Tonometry. This measures the pressure inside your eye.
Mr Tarun Sharma's leaflets in Emma's library explain some of these tests in more detail: visual field testing, eye pressure and gonioscopy.
Source: NHS · US National Eye Institute · MedlinePlus (US National Library of Medicine)
Treatment
The NHS and the National Eye Institute describe three main treatments:
- Eye drops. These are the most common treatment. They lower the pressure in the eye. Some help fluid drain out of the eye. Others reduce the amount of fluid the eye makes.
- Laser treatment. This also lowers the pressure in the eye. The National Eye Institute says it is a simple procedure that the doctor can do in the clinic.
- Surgery. The National Eye Institute says your doctor might suggest surgery if medicines and laser treatment do not work. There are several types.
Health New Zealand says that there is no cure for glaucoma, but treatment controls it, and that treatment continues for the rest of your life. You will also have follow-up appointments to check that the treatment is working. The NHS says it is important not to miss any of them.
Source: NHS · US National Eye Institute · US National Eye Institute · Health New Zealand | Te Whatu Ora
Living with eye drops
The National Eye Institute says that, depending on the medicine, drops are used once, twice, or up to 4 times a day. It also explains why the daily routine matters: the drops do not make you feel different or improve your vision. They prevent your vision from getting worse. If you do not use them as prescribed, you could lose your vision.
Putting drops in
The National Eye Institute describes these steps:
- Wash your hands with soap and water.
- Tilt your head back and look up.
- With one hand, pull the lower eyelid down and away from the eye. This makes a pocket for the drop.
- With the other hand, hold the bottle upside down, with the tip just above the pocket. Squeeze the prescribed number of drops into the pocket. Do not let the tip touch the eye or the eyelid.
- Close the eye, and press a finger lightly on the inner corner of the eye for at least 1 minute. This keeps the drop from draining into the nose.
- If you use more than one type of drop, wait at least 5 minutes between each type.
If you find drops hard to put in, the National Eye Institute suggests asking your eye doctor about special tools that can help. Mr Sharma's leaflet How to instil eye drops also explains the technique.
Side effects
The National Eye Institute says most people do not have problems with glaucoma medicines. If you notice a side effect, talk to your doctor. You may be able to use a different dose or a different medicine. Health New Zealand says that if your eyes are always sore, your vision is blurred, or you get a red rash around your eyes, you should speak to your healthcare provider as soon as possible.
Source: US National Eye Institute · US National Eye Institute · Health New Zealand | Te Whatu Ora
Questions to take to your appointment
Many people forget their questions once they are in the room. It helps to write them down before you go. Some questions that people often ask:
- What type of glaucoma do I have?
- How much has it affected my sight so far?
- What may have caused it?
- What is my treatment, and how do I use it?
- What side effects should I tell you about?
- When is my next check-up?
- Should my close relatives have their eyes tested?
Also bring a list of every medicine, supplement and vitamin you take. The National Eye Institute says glaucoma eye drops may affect how other medicines work, so your doctor needs to know about all of them.
Source: US National Eye Institute
Your family
The NHS says your risk of glaucoma may be higher if you have a brother, sister or parent with it. People at higher risk may be advised to have eye tests more often. The National Eye Institute suggests encouraging family members to get checked, because glaucoma can run in families.
Glaucoma often has no symptoms at first. A routine eye test can find it early. Your relatives can tell their optician or optometrist that glaucoma runs in the family.
Source: NHS · US National Eye Institute
Driving (UK)
If you live in the UK, GOV.UK says you must tell the DVLA about glaucoma if it affects both eyes, or if it affects one eye and you only have vision in that eye. You must also tell them if a GP, optician or eye specialist has said you should not drive.
Driving rules are different in other countries. Ask your eye doctor what applies where you live.
Source: GOV.UK (DVLA)
When to get help urgently
Source: NHS · US National Eye Institute
How Emma can help
Emma is a companion for life with glaucoma. She lives on your phone.
- Ask anything, any time. Type or speak a question about glaucoma, and Emma answers in plain English, with the source shown. She can read the answer aloud.
- Spoken reminders for your drops and your appointments.
- A Journey Log for your eye-pressure readings and notes, with a summary you can take to your appointment.
- A reader for small print. Point the camera at a label or a leaflet, and Emma reads it aloud.
Emma: a glaucoma companion created by doctors.
Everything stays on your phone. Pay once, keep it for life.
Where this comes from
Every statement on this page comes from public health guidance. We checked each one against the live page of its source on 19 October 2026. Guidance can change, so the live page is always the most current version.
- Glaucoma — NHS. Page last reviewed 13 June 2025.
- Glaucoma — US National Eye Institute.
- Glaucoma medicines — US National Eye Institute. Last updated 5 December 2024.
- How to put in eye drops — US National Eye Institute. Last updated 5 December 2024.
- Glaucoma — MedlinePlus (US National Library of Medicine).
- Glaucoma (Papahewa) — Health New Zealand | Te Whatu Ora.
- Eye conditions and driving — GOV.UK (DVLA).