Glaucoma: A Guide

What Is Glaucoma?

Glaucoma is the name for a group of eye conditions in which the optic nerve is damaged at the point where it leaves the eye.

The nerve carries information from the light-sensitive layer in your eye, the retina, to the brain, where it is perceived as a picture. Your eye needs a certain amount of pressure to keep that eyeball in shape so it can work properly. In some people, the damage is caused by raised eye pressure.

Others may have pressure within normal limits, but the damage occurs because of weakness in the optic nerve. In most cases, both factors are involved, though to varying degrees. Eye pressure is largely independent of blood pressure.

 

Why Can Increased Eye Pressure Be Serious?

If the optic nerve comes under too much pressure, then it can be injured. How much damage will depend on how much pressure and how long it has been under pressure. Really high pressure will damage the optic nerve immediately. A lower level of pressure can cause damage more slowly, and then you would gradually lose your sight if it were not treated.

 

What Are The Different Types of Glaucoma?

There are two types of glaucoma: chronic (slow) and acute (sudden) glaucoma.

Chronic Glaucoma

This is the more common type, in which eye pressure rises very slowly, and there is no pain to indicate a problem, but the field of vision gradually becomes impaired.

The early loss in the field of vision is usually in the shape of an arc, slightly above or below the centre when looking straight ahead. This blank area spreads both outward and inward if glaucoma is left untreated. The centre of the field is last affected, so that eventually you’re left with tunnel vision. In time, sight can be lost altogether.

 

Acute Glaucoma

Acute glaucoma is much less common in Western countries. This happens when there is a sudden rise in eye pressure. This can be painful and will cause permanent damage to your sight if not treated promptly.

The affected eye becomes red, the vision deteriorates, and may even black out. There may also be nausea and vomiting. In the early stages, you might see misty rainbow colours around white lights. Sometimes people have a series of mild attacks.

 

What Are the Early Symptoms of Glaucoma?

Glaucoma is often called the silent thief of sight because, in its most common form, it develops more slowly and without obvious warning signs.

In the early stages, most people do not notice any symptoms at all. Vision in the centre may stay clear while subtle changes begin in the peripheral (side) vision.

When symptoms do appear, they can include:

• Gradual loss of peripheral vision
• Difficulty seeing in low light
• Seeing halos around lights
• Mild blurred vision (often inconsistent)

In acute glaucoma, symptoms are very different and urgent:

• Severe eye pain
• Sudden blurred vision
• Headache or nausea
• Red eye
• Seeing rainbow-coloured halos around lights.

If these sudden symptoms occur, it is important to seek our urgent eye care immediately.

 

Can Glaucoma Cause Blindness?

Yes, glaucoma can lead to permanent vision loss if it is not diagnosed and managed in time.

However, it is important to understand:

• Vision loss from glaucoma is preventable in most cases
• Damage that has already occurred cannot be reversed
• Early detection and treatment are key to protecting sight

Glaucoma typically affects peripheral vision first, and many people only notice changes once the condition is more advanced. With regular eye tests, it is usually possible to slow or stop progression before significant vision loss occurs.

 

What Causes Glaucoma?

Glaucoma is most commonly caused by increased pressure inside the eye (intraocular pressure). This pressure can damage the optic nerve over time.

However, not all glaucoma is linked to high pressure.

Common contributing factors include:

• Build-up of fluid in the eye that doesn’t drain properly
• Damage to the optic nerve (sometimes even at normal pressure)
• Reduced blood flow to the optic nerve

In many cases, the exact cause isn’t fully clear, but the result is the same: gradual damage to the nerve responsible for vision.

 

Who Is At Risk Of Glaucoma?

Anyone can develop glaucoma, but some people are at higher risk.

You may be more likely to develop if you:

• Are over the age of 40 (risk increases with age)
• Have a family history of glaucoma
• Are of African, Caribbean, or Asian heritage
• Have diabetes or high blood pressure
• Are very short-sighted (myopic) or long-sighted (hyperopic)
• Have previously had an eye injury or surgery

Because many risk factors are silent, regular eye examinations are essential even if your vision seems fine.

Book an appointment with Opticare here.

People over the age of 40 and with a family history of glaucoma, such as parents, children, or siblings diagnosed with glaucoma, are entitled to a free sight test every year under the NHS.

For more information on who qualifies for a free NHS eye test, read our guide here.

 

Glaucoma Treatment Options

Whilst glaucoma cannot be cured, it can usually be controlled very effectively.

Treatment aims to lower eye pressure and prevent further damage.

Treatment for Chronic Glaucoma:

You will need to go to the hospital for treatment and have regular check-ups afterwards. Treatment to lower pressure is usually started with eye drops. If this does not help, your optometrist may suggest either laser treatment or an operation called trabeculectomy to improve the drainage of fluid from your eye.

Treatment for Acute Glaucoma:

If you have an acute attack, you will need to go to the hospital immediately so that the pain and pressure in the eye can be relieved. Drugs will be given to reduce the pressure.

When the pain and inflammation have gone down, your surgeon will advise making a small hole in the outer border of the iris to relieve the obstruction and allow the fluid to drain away. This is usually done by laser treatment or a small operation. Usually, the surgeon will advise you to have the same treatment on the other eye, because there is a high risk that it will develop the same problem.

 

Living With Glaucoma

Most people living with glaucoma continue to lead full, active lives.

Key aspects of living with the condition include:

• Using prescribed eye drops consistently
• Attending regular eye appointments to monitor pressure and vision
• Protecting remaining vision through early intervention
• Making small lifestyle adjustments in vision is affected

Some people may notice changes in peripheral vision over time, but central vision can often remain good for many years with proper management.

Support from your optometrist is essential. Regular monitoring ensures that any changes are detected early and treatment can be adjusted as needed.

Will I Still Be Able to Drive?

Most people can still drive if the loss of visual field is not too advanced. To assess possible damage to your peripheral vision, you will need a special test to see if your sight meets the standards of the DVLA.

 

Glaucoma Screening at Opticare

Glaucoma screening is part of our standard eye examination. It helps us ensure you can see well, that your eyes work properly, and that they are healthy and free of disease.

This test involves:

• Measurement of the intraocular pressures
• Examination of the optic disk
• Visual field assessment

OptiPlan members also receive a more in-depth glaucoma risk analysis, with an OCT scan included in their enhanced eye examination. See the full benefits of OptiPlan membership here.

 

 

Our Other Eye Condition Guides:

• Our guide on cataract awareness can be found here.
• Our guide on age-related macular degeneration (AMD) can be found here.
• Our guide on diabetic retinopathy can be found here