Expert reviewer, Simon Taylor, Professor of Ophthalmology and Consultant Ophthalmic Surgeon
Next review due June 2020

Glaucoma is the name for a group of eye conditions where your optic nerve (the nerve that connects your eye to your brain) is damaged and your vision becomes worse. Glaucoma can affect both of your eyes, but one eye may be affected more than the other. Vision that has been lost can’t be restored but if you have treatment early, it can prevent further sight loss.

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What is glaucoma?

If you have glaucoma, your optic nerve (the nerve that connects your eye to your brain) is damaged at the point where it leaves your eye.

Often, this damage is the result of an increase in pressure in your eye. This may happen when fluid (the aqueous humour) in the front part of your eye (the anterior chamber) doesn’t drain away properly. Usually, the amount of fluid produced in your eye is balanced by the amount draining away, so the pressure in your eye stays the same. If you have a problem with draining away the fluid in the front of your eye, the pressure within your eye can become so high that your optic nerve is damaged. Because of this, you may begin to lose your sight.

Although raised pressure in your eye is the most common cause of glaucoma, the condition can also be caused by other things. For example, a weakness in your optic nerve. This can lead to damage even when the pressure in your eye appears to be normal. In most people, glaucoma is caused by a combination of high pressure and a weakness in the optic nerve. For more information see our Causes section.

Types of glaucoma

Glaucoma isn’t a single disease – it’s a group of conditions. The main types are:

  • open angle glaucoma
  • normal tension glaucoma
  • angle closure glaucoma
  • secondary glaucoma
  • glaucoma in babies and children

There is more detail about each of these below.

Open angle glaucoma

Open angle glaucoma is the most common type, affecting seven out of 10 people with glaucoma. It usually develops very slowly, and is referred to as chronic or primary open angle glaucoma. Damage to your eyesight happens gradually.

You can get open angle glaucoma if the fluid in your eye can’t pass through the drainage channels properly. There’s usually no obvious reason for the blockage.

This can slowly raise the pressure within your eye and damage your optic nerve.

Normal tension glaucoma

This is another form of chronic glaucoma that can occur even if the pressure in your eye is within the normal range. The normal range is between 10 and 21 millimetres of mercury (mm Hg). It’s thought that in this type of glaucoma, the optic nerve may have a poor blood supply or a weakness.

Angle closure glaucoma

Angle closure glaucoma can be acute (happens very quickly) or chronic (long-term) and develop more slowly.

It’s a particular problem when it’s acute, meaning the pressure in your eye rises very quickly. Your cornea (the clear window at the front of your eye) comes into contact with your iris (the part that gives your eye its colour). This prevents fluid in your eye from flowing out of your eye as normal.

Acute angle closure glaucoma can make your eye red, be very painful, cause blurred vision and you may see coloured halos around lights. You must seek urgent medical attention. It can cause permanent blindness unless treated quickly. It’s also linked to being long-sighted and to developing cataracts.

Secondary glaucoma

This is an uncommon form of glaucoma you can get if you have other eye conditions, including an injury to your eye or repeated inflammation.

Glaucoma in children and babies

Glaucoma can develop at any age. Congenital (or developmental) glaucoma is a very rare condition where a baby is born with glaucoma. This happens when the eye’s drainage system doesn’t develop properly before birth. Developmental glaucoma has been linked to other conditions in children, including arthritis and cataracts.

Symptoms of glaucoma

Open angle glaucoma

Glaucoma often starts in one eye. However, you may not notice the loss of vision in the affected eye because sight in your other eye remains normal. Another reason you might not notice is because the sight loss is gradual with chronic open angle glaucoma. Furthermore, the first part of your sight to be affected is the outer or peripheral field of vision. Your central vision isn’t usually affected until much later. If your field of vision has narrowed, you might notice you bump into things more often or trip down kerbs and steps.

Usually, chronic open angle glaucoma doesn’t cause any pain in your eye.

Angle closure glaucoma

Symptoms of acute angle closure glaucoma often include a combination of:

  • loss of sight
  • blurred vision or a halo around lights
  • pain in your eye
  • headache
  • feeling sick or vomiting
  • redness in the white of your eye
  • fixed and semi-dilated pupils

If you notice these symptoms, seek urgent medical attention straight away.

Chronic angle closure glaucoma is less noticeable. It’s often detected during routine eye tests.

Congenital glaucoma

The signs of congenital (or developmental) glaucoma include watering eyes, sensitivity to light or cloudy and unusually large eyes. Vision may be poor. These symptoms may be caused by something else, but if your child has any of them, ask your GP for advice. If they suspect glaucoma, they’ll refer your child to a paediatric ophthalmic specialist (an expert in eye conditions in children).

Diagnosis of glaucoma

You may not have any symptoms until you start to lose your sight. So screening tests are important to detect glaucoma. An optometrist – a registered health professional who examines eyes, tests sight and dispenses glasses and contact lenses – can do these during a routine eye test.

As glaucoma is more common if you’re over 40, it’s important to have an eye test at least every two years from this age onwards. You should be tested more often if you’re at risk of developing glaucoma – for example, if you have a close family member with the condition.

There are a number of quick and painless tests for glaucoma. Your optometrist may carry out the following.

  • Look at your optic nerve by shining a torch into your eye. 
  • Measure the pressure in your eye using a tonometry test – a small amount of pressure is applied to your eye using a warm puff of air. Another type of tonometry test physically checks the pressure using a small tool. You’ll be given anaesthetic eye drops first so you won’t feel anything.
  • Measure your field of vision in a perimetry test – you may be asked to look out for a light that flashes in your side vision.

Individually these tests may be inconclusive, but together the results give a clear indication if you’re developing glaucoma. 

For accuracy, your optometrist may measure your eye pressure and field of vision twice on separate occasions if they think you may have glaucoma. They’ll usually then refer you to an ophthalmologist for more tests. An ophthalmologist is a doctor who specialises in eye health, including eye surgery.

Your ophthalmologist may want to check how thick your cornea is. This is a good indicator that high pressure in your eye is developing into glaucoma. They’ll probably look at the structure of the area where fluid drains out of your eye to see if there is any obstruction (blockage). They may want to do different scans of your eye, including an ultrasound or a scan called optical coherence tomography.

Babies and children under five with suspected glaucoma will usually be under general anaesthesia for any tests and examinations.

Treatment of glaucoma

Treatment for glaucoma aims to lower the pressure inside your eye and reduce the risk of further damage to your sight. Treatment can’t reverse any existing damage, so it won’t improve your sight if this has already become poor. Your optometrist and ophthalmologist will want to monitor you regularly. This may be every three to 12 months, depending on how far your glaucoma has progressed when you’re first diagnosed.


Normal treatment for glaucoma involves using eye drops at least once a day. They usually contain the following types of medicine. Your doctor will suggest the most suitable one for you and your type of glaucoma.

  • Prostaglandin analogues and prostamides. These help your eye’s internal fluid to drain out more quickly. They may change your eye colour and make your eyelashes grow more.
  • Beta-blockers. These reduce the pressure in your eye and lower the production of fluid in your eye. You shouldn’t be treated with beta-blockers if you’ve got a heart condition or breathing problems like asthma.
  • Carbonic anhydrase inhibitors. These lower the pressure in your eye by reducing the amount of fluid your eyes produce. They’re often prescribed as an alternative to beta-blockers.
  • Sympathomimetics. These reduce pressure in your eye and help to drain away the fluid build-up.
  • Miotics. These improve the flow of fluid from your eye, but aren’t suitable if you’re pregnant or breastfeeding, or have certain conditions, including epilepsy. They’re usually only prescribed for secondary glaucoma and angle closure glaucoma.

You may be offered these separately, or in combination. It’s important that you follow your ophthalmologist’s advice and use your medicines as they advise you. Always read the patient information leaflet that comes with your medicine.

Speak to your ophthalmologist as soon as possible if you think your medicine is causing a side-effect. For instance, if you notice changes in your vision or have eye pain.

If your eyes get itchy, red or swollen, you could be allergic to the medicine or preservatives commonly used in eye drops.

Your doctor may be able to offer you another type of treatment, including preservative-free eye drops. But don’t stop using your eye drops without talking to them first.

Laser treatment

Laser treatment helps the draining system in your eye work better. Laser treatment may also be used to make a small hole in your iris, to help fluid drain away.

If you decide to have laser treatment, you’ll be offered a local anaesthetic. This completely blocks pain from the eye area and you will stay awake during the procedure. You will usually be able to go home the same day. Laser treatments are minor procedures and most people recover from them quickly. You’ll usually need to continue using eye drops after your treatment, to keep the pressure in your eye stable.

You may also be offered a laser procedure to treat or prevent acute angle closure glaucoma.


If other treatments haven’t worked for you, your ophthalmologist may suggest laser treatment or an operation. They’ll usually try a couple of different medicines first, and make sure you’re using your eye drops properly. Certain types of glaucoma laser treatment and surgery are particularly suitable for babies and children. There is a range of operations.

Trabeculectomy surgery

This is one of the most commonly performed operations. A tiny opening is created in the white part of your eye (the sclera) to allow fluid to drain away. Clinical studies show this successfully lowers eye pressure in the long term for up to nine out of 10 people. Some people may need further treatment. This could be another operation or continuing with eye drops. Serious complications like infection or bleeding in the eye are rare.

The surgery can be done under local or general anaesthesia, and you may not have to stay in hospital overnight. You’ll need regular follow-up checks on your eye pressure and you’ll be given special eye drops to prevent infection and swelling. You may feel some discomfort and your vision may be a bit blurred for a few weeks afterwards. You’ll need to take time off work.

Urgent treatment

Acute angle closure glaucoma is a medical emergency and you’ll need to have treatment straight away. You’ll probably be given eye drops, which may include beta-blockers, sympathomimetics or a carbonic anhydrase inhibitor, such as acetazolamide. You may be advised to lie in a way that relieves the pressure in your eye. Painkillers and emetics to stop nausea can help with symptoms. In some urgent cases, laser treatment or surgery on your iris may be necessary.

New and emerging treatments

Technology has advanced rapidly and new types of operation are now becoming available. There’s a lot of research in this area and short-term results of some of these techniques look good. But there’s not a great deal of long-term data yet.

These new procedures are usually done under local anaesthesia. For example, there’s a less invasive form of trabeculectomy that just removes a small strip of tissue.  

Or you could have a very small stent (hollow tube) inserted through a small cut in your eye to help drain fluid and reduce pressure. This can work for up to five years and you may not need to use eye drops as well. It may feel a little sore at first and in a few instances another operation is sometimes needed to reposition or replace the stent.

If you’d like to know more about your treatment options, speak to your doctor. Some techniques have been developed so glaucoma can be treated at the same time as cataracts.

Causes of glaucoma

Glaucoma is caused by an increase in pressure within your eye (intraocular pressure) or a weakness in the optic nerve or both. Raised pressure doesn’t mean you’ll automatically get glaucoma.

Risk of open angle glaucoma

You’re more likely to get glaucoma later in life, particularly over the age of 65. For example, chronic open angle glaucoma is uncommon in people under 40. It affects about two in 100 people aged over 40 (although half are unaware they have it) and around 10 in 100 people over 70. Other factors that can increase your chances of getting open angle glaucoma include:

  • your ethnicity – you’re more at risk developing the condition if you’re from a black origin 
  • a family history of glaucoma – your risk is almost four times higher if your parents or siblings have glaucoma
  • being short-sighted
  • having diabetes (both type 1 and especially type 2)
  • high blood pressure especially in older people, and cardiovascular disease
  • using steroids for a long time, particularly in creams used near your eyes
  • conditions that restrict the flow of blood to your eyes or cause swelling

Risk of angle closure glaucoma

Women are more likely to develop angle closure glaucoma than men, particularly when they’re older. It’s related to the shape of your eye, which could be hereditary.

You’re also more likely to develop the condition if you’re far-sighted or from an Asian ethnicity. Acute angle closure glaucoma is most common in people aged between 55 and 65.

Prevention of glaucoma

Glaucoma can’t be prevented, but its progression can be slowed with treatment.

Two in 10 people have lost some peripheral (outer) vision by the time they’re diagnosed with glaucoma. But prompt treatment usually means you can expect to keep a level of vision where you can carry out your usual routine and daily life.

If you’re over 40, you should have an eye test every two years. A routine test will check for the early signs of glaucoma, especially increased pressure in your eye. This is the main symptom of glaucoma and can be treated.

It’s particularly important to be tested for glaucoma regularly if one of your parents, children, or a brother or sister has glaucoma.

If you have a close relative that has glaucoma, experts recommend that you should be checked every:

  • three to five years if you’re between 20 and 29 years old 
  • two to four years if you’re between 30 and 64 years old 
  • one to two years from 65 years onwards

If you’d like more information, ask your optometrist for advice. If you’re known to be at risk, these regular checks should be free.

Living with glaucoma

Being diagnosed with glaucoma shouldn’t stop you doing everyday activities like watching television, using computers or reading. These won’t affect the pressure in your eyes or do any further damage.

You can also carry on with most sports and hobbies. Regular physical activity is good for your overall health and usually reduces rather than raises eye pressure. But check with your doctor if you plan to go scuba diving. You should also speak to them if you play a wind instrument, because this activity can temporarily increase eye pressure.

It’s generally safe to fly with glaucoma. Your eyes will adjust to changes in cabin pressure. But ask your doctor’s advice if you also have circulatory problems.

Pressure inside your eye naturally increases when you’re pregnant. If you’ve been diagnosed with glaucoma and are pregnant or breastfeeding, talk to your doctor about the most suitable treatment.

If glaucoma has affected your eyesight, consider changes to make life easier, like using brighter lights in your home.

You can ask your ophthalmologist, social services or GP for advice on support available if your sight is impaired.

Frequently asked questions

  • A lot of people with glaucoma find it difficult to stick to their medication. If you forget a dose, put in your eye drops as soon as you remember.

    It isn’t a problem if you forget to use your eye drops on the odd occasion. However, it’s important to get into a routine of using your eye drops at around the same time every day to help you remember.

    Try using a chart with tick boxes to keep a check on whether you’ve taken your eye drops every day. You could also set a timer to ring at a particular time to remind you when you need to put them in.

    Using your drops regularly, as advised by your doctor, offers the best protection against glaucoma. Although your vision can’t be restored, regularly using your eye drops can help to stop you losing any more sight.

    If for any reason you can’t use your eye drops regularly, speak to your doctor to talk through the problem and see if there is an alternative treatment they can offer you.

  • Scientists have been looking at whether taking certain nutritional supplements, including vitamins, can help people with glaucoma. However, at the moment, they haven’t found any proof that supplements can help treat glaucoma.

    In particular, tests have shown that ginkgo biloba might have positive effects on the changes in your eye that might lead to glaucoma. It may be used by some glaucoma specialists for certain forms of the condition. But there’s not enough evidence to say if it helps generally. It can also have side-effects and interact with commonly used medicines, like anticoagulants that thin your blood, including aspirin.

    Talk to your pharmacist or GP before taking any supplements. A healthy, balanced diet should supply all the vitamins and minerals you need.

  • Your ophthalmologist (a doctor who specialises in eye health) or optometrist (a registered health professional who examines eyes) will monitor your condition. They will check if your treatment is working.

    You should follow your ophthalmologist’s advice on using eye drops or the pressure in your eyes could rise and cause further damage the optical nerve. Don’t stop using eye drops without first talking to your doctor. They will probably be able to suggest an alternative treatment that suits you better, including eye drops that combine different medicines.

    You’ll probably need to go to an eye clinic regularly for tests. For instance, a thorough assessment of your field of vision can accurately tell if your sight has got worse or stayed the same.

    It’s important to attend these appointments to check your treatment is working, especially if you don’t have any symptoms. You’ll also need regular check-ups after laser treatment or surgery, even if you no longer need to use eye drops.

    Once you’ve developed glaucoma, you’ll need treatment for it for the rest of your life. This includes monitoring the pressure in your eye. If it rises, you could permanently lose more of your sight.

  • As long as your central and peripheral vision are good enough to meet the national recommended guidelines for driving, you should still be able to drive.

    If you have severe glaucoma in both eyes, you’ll need to report it to the Driver and Vehicle Licensing Authority (DVLA). You face a fine if glaucoma affects your driving and could be prosecuted if you’re involved in an accident as a result.

    However, if glaucoma affects only one of your eyes you don’t need to tell the DVLA, provided you don’t have a medical condition affecting your other eye.

    When you inform the DVLA that you have glaucoma, you’ll be asked to complete a medical questionnaire about your condition, including which eye is affected. The form asks about medicines you’re taking and how your glaucoma is being monitored. You’ll be asked for consent so the DVLA can get more information on your health from your ophthalmologist (a doctor who specialises in eye health) and GP.

    You’ll need to fill in a separate form if you have a bus, coach or lorry licence.

    The DVLA may want you to have a medical exam or practical assessment by an independent optometrist to check if it’s safe for you to drive. They are looking to check that your visual acuity (how clearly you can see) and your field of vision meet the requirements for driving safely. If your eye sight isn’t good enough to meet the DVLA’s standards, you won’t be able to drive again.

    Ask your optometrist or ophthalmologist for advice on driving and any tests you may need to have.

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  • Reviewed by Natalie Heaton, Specialist Health Editor, Bupa Health Content Team, June 2017
    Expert reviewer, Simon Taylor, Professor of Ophthalmology and Consultant Ophthalmic Surgeon
    Next review due June 2020

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