Glaucoma is an eye condition where your optic nerve is damaged by the pressure of the fluid inside your eye. Most types of glaucoma have no symptoms, so a regular eye test is the only way to know you have the condition. Treatment with drops can often prevent glaucoma causing sight loss.

Download our Understanding Glaucoma guide

Our Understanding Glaucoma guide is accredited by the Royal College of Ophthalmologists. It’s designed to give you a detailed understanding of your eye condition and helpful advice on next steps.

Understanding glaucoma

Glaucoma is the name given to a group of eye conditions that cause permanent sight loss by damaging your optic nerve.

You may not notice any difference in your vision because glaucoma affects your peripheral vision (also known as your side vision) first. As your peripheral vision is not as sensitive as your central vision, it’s difficult to notice any early changes to your vision – but your sight is being damaged.

There is no treatment to restore sight loss caused by glaucoma but treatments, such as eye drops and laser surgery, can help prevent sight loss from happening.

Causes of glaucoma

Glaucoma can be caused by raised eye pressure or a weakness in your optic nerve.

Your eye needs a certain amount of pressure to keep the eyeball healthy and in the right shape. But if the pressure is too high, it can cause your optic nerve to become damaged at the point where it leaves your eye.

Types of glaucoma

For a more in-depth look at each type of glaucoma, their causes and specific treatments download our Understanding Glaucoma guide.

Primary open angle glaucoma (POAG)

Primary open angle glaucoma is the most common type of glaucoma. It’s a chronic condition which means the damage to your optic nerve and changes to your sight happen very slowly over time. 

Acute angle closure glaucoma

Acute angle glaucoma happens when your eye pressure rises very suddenly. It’s very painful and can causes permanent damage to your sight if it’s not treated quickly.

Secondary glaucoma

This is when glaucoma occurs as a result of another eye condition, an operation, injury or medication.

Congenital glaucoma

Congenital glaucoma is a very rare condition that affects young babies. It’s usually diagnosed in early years and managed by specialist clinics.


All treatment for glaucoma aims to lower your eye pressure to prevent damage to your optic nerve and your sight.

Treatment to lower your eye pressure usually starts with eye drops, and for most people with glaucoma, this is all the treatment they will ever need.

Sometimes, laser treatment or surgery may also be needed to help control your eye pressure and prevent sight loss.

Your ophthalmologist (hospital eye doctor) will be able to discuss the best treatment for you. You can take a more in-depth look at the different treatments for each type of glaucoma in our Understanding Glaucoma download guide (see the top of this page).

Alex's top tips for putting in eye drops

Recently diagnosed with glaucoma 

Lots of people who have treatment for their glaucoma don't have any sight problems because the treatment prevents sight loss.

But if your glaucoma does cause changes to your sight, we’re here to support you every step of the way – just give our Helpline a call. You might also find it helpful to talk to our Eye Health team about your eye condition, get support from our Sight Loss Counselling service, or find out how to register as sight impaired.

Below are some guides that may be useful:

Getting emotional support

Benefits, concessions and registering as sight impaired

For information about Northern Ireland please download our Benefits, Concessions and Certification in Northern Ireland leaflet: 

Staying in work 


Knowing RNIB is there is so reassuring, like a comfort blanket

Peter Seaman

You can get support with your eye condition with RNIB


Living confidently with glaucoma

We can help you maximise your vision and make the most of the sight you have. You can contact our Helpline for support, or start by reading our guides on making the most of your sight and on enjoying leisure when living with sight loss.

Making the most of your sight

Leisure pursuits when you have sight loss

Managing your money 

If you haven’t already, why not join RNIB Connect and get connected to other people affected by sight loss locally and across the country? Or try our free Talking Books service to enjoy reading in an accessible format, or tune into RNIB Connect Radio to hear news, information and advice for people affected by sight loss.

Products from our shop that could help

Helpful organisations

The International Glaucoma Association provides support and information to people with glaucoma

The NHS Choices website has information about glaucoma.

How to get involved

About this guide

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