Glaucoma is an eye condition where the optic nerve, which connects your eye to your brain, becomes damaged. It can lead to loss of vision if not detected and treated early on.
It usually occurs when the fluid in the eye cannot drain properly, which increases the pressure inside the eye and puts pressure on the optic nerve.
Glaucoma is a common condition, but many people won't realise they have it because it doesn't always cause symptoms in the early stages.
It can affect people of all ages, including babies and young children, but is most common in adults in their 70s and 80s.
This page covers
When to get medical advice
Tests and diagnosis
Symptoms of glaucoma
Glaucoma doesn't usually have any symptoms to begin with and is often only picked up during a routine eye test.
Many people don't realise they have it because it develops slowly over many years and tends to cause a loss of peripheral vision (the edge of your vision) at first.
Both eyes are usually affected, although it may be worse in one eye. Without treatment, it can eventually lead to blindness.
Very occasionally, glaucoma can develop suddenly and cause:
- intense eye pain
- a red eye
- a headache
- tenderness around the eyes
- seeing rings around lights
- blurred vision
When to get medical advice
Visit an opticians or your GP if you have any concerns about your vision.
If you have glaucoma, early diagnosis and treatment can help stop your vision getting worse.
If you develop symptoms of glaucoma suddenly (see above), go to your nearest eye casualty unit or accident and emergency (A&E) department as soon as possible.
This is a medical emergency that may require immediate treatment.
Types of glaucoma
There are several different types of glaucoma.
Some of the main types are:
- primary open angle glaucoma – the most common type, which tends to develop slowly over many years
- primary angle closure glaucoma – an uncommon type that can develop slowly or quickly
- secondary glaucoma – glaucoma caused by an underlying eye condition, such as uveitis (inflammation of the eye)
- normal tension glaucoma – where the pressure inside the eye is at a normal level
- childhood glaucoma (congenital glaucoma) – a rare type that occurs in very young children, caused by an abnormality of the eye
Read more about the types of glaucoma.
Causes of glaucoma
Glaucoma is usually caused by a blockage in the part of the eye that allows fluid to drain from it. This can lead to a build-up of fluid and pressure in the eye and can damage the optic nerve.
It's often unclear exactly what causes it, although there are some things that can increase your risk, including:
- your age – glaucoma becomes more likely as you get older and the most common type affects around 1 in 10 people over 75
- your ethnicity – people of African, Caribbean or Asian origin are at a higher risk of glaucoma
- your family history – you're more likely to develop glaucoma if you have a parent or sibling with the condition
It's not clear whether you can do anything to prevent glaucoma, but having regular eye tests will help ensure it's picked up as early as possible.
Read more about the causes of glaucoma.
Tests for glaucoma
Glaucoma can usually be detected during a routine eye test at an opticians, often before it causes any noticeable symptoms.
You should have a routine eye test at least every two years. Find out if you're eligible for free NHS eye tests.
Several quick and painless tests can be carried out to check for glaucoma, including measurements of the pressure inside your eye and tests of your peripheral vision.
If tests suggest you have glaucoma, you should be referred to an ophthalmologist (eye doctor) to discuss treatment.
Read about how glaucoma is diagnosed.
Treatments for glaucoma
It's not possible to reverse any loss of vision that occurred before glaucoma was diagnosed, but treatment can help stop your vision getting any worse.
The treatment recommended for you will depend on the type of glaucoma you have, but the main treatments are:
- eye drops – to reduce the pressure in your eyes
- laser treatment – to open up the blocked drainage tubes in your eyes or reduce the production of fluid in your eyes
- surgery – to improve the drainage of fluid from your eyes
You'll also probably need regular appointments to monitor your condition and ensure treatment is working.
Read more about how glaucoma is treated.
Outlook for glaucoma
The outlook for glaucoma largely depends on the type of glaucoma you have, but generally:
- it often results in some degree of permanent vision loss, although most people retain useful vision for life
- it may affect your ability to do certain tasks, such as driving
- only a small proportion of people will end up totally blind
The outlook is better the earlier glaucoma is diagnosed and treated.
This is why it's so important to get your eyes tested regularly and to make sure you follow your recommended treatment plan.