Glaucoma is often referred to by eye care professionals as the ‘silent thief of sight’, and for good reason. It can creep up on you slowly, stealing your peripheral vision before you even realise there is a problem.
For many people, the terrifying reality is that by the time they notice significant changes in their eyesight, permanent damage has already occurred. This makes understanding the symptoms of glaucoma and attending regular eye examinations absolutely critical for preserving your vision.
While this condition is more common in older adults, it can affect people of all ages. The World Health Organization (WHO) estimates that glaucoma is the second leading cause of blindness globally, highlighting the urgent need for awareness.
It is easy to assume that if your eyes feel fine, they are healthy. However, many forms of this disease are initially asymptomatic. Taking a proactive approach to your eye health is the single best way to protect your sight for the future.
In this article, we will explore the early warning signs you should never ignore, the different types of glaucoma, and the actionable steps you can take today to safeguard your vision.
What is Glaucoma?
To understand the symptoms, it helps to understand the mechanics of the eye. Glaucoma is a group of eye conditions that damage the optic nerve, the health of which is vital for good vision. This damage is often caused by an abnormally high pressure in your eye.
Your eye constantly produces a fluid called aqueous humour. As new fluid flows into your eye, the same amount should drain out through a specific drainage angle. This process keeps pressure in the eye (intraocular pressure or IOP) stable.
However, if the fluid creates a backlog because the drainage angle is not working correctly, the pressure builds up. Over time, this increased pressure erodes the delicate fibres of the optic nerve.
Key factors to remember:
- The Optic Nerve: This is the cable that sends visual messages from your retina to your brain.
- Intraocular Pressure: While high pressure is a major risk factor, Healthline explains that glaucoma can strictly occur even with normal eye pressure, known as normal-tension glaucoma.
- Irreversibility: Vision lost to glaucoma cannot be recovered, which is why early detection is paramount.
Symptoms of Glaucoma: Signs to Watch For
The symptoms you might experience depend entirely on the type of glaucoma you have. Broadly speaking, there are two main categories: chronic (slow-developing) and acute (sudden onset). Knowing the difference could save your sight.
1. Primary Open-Angle Glaucoma (The Silent Type)
This is the most common form of the disease. It happens gradually, where the eye does not drain fluid as well as it should (like a clogged drain). The result is eye pressure building over time.
Early signs:
- No pain: This type is typically painless.
- Blind spots: Patchy blind spots in your side (peripheral) or central vision, frequently in both eyes.
- Tunnel vision: In advanced stages, you may feel like you are looking through a tube.
Because these changes are so slow, your brain often compensates for the missing visual information, masking the problem until it is severe. This is why the NHS emphasises that regular eye tests are often the only way to detect it early.
2. Acute Angle-Closure Glaucoma (The Emergency)
This type is less common but requires immediate medical attention. It occurs when the iris is very close to the drainage angle in the eye. The iris can block the drainage angle completely, causing eye pressure to rise very quickly.
Warning signs include:
- Severe headache: Often throbbing and intense.
- Eye pain: Sharp pain in the eye itself.
- Nausea and vomiting: Accompanied by eye pain.
- Blurred vision: Sudden onset of fuzziness.
- Haloes around lights: Seeing rainbow-coloured rings around light bulbs or streetlights.
- Redness: The white of the eye becomes red.
If you experience these symptoms, go to an Accident and Emergency (A&E) department immediately. Delaying treatment can lead to blindness in a matter of hours.
3. Normal-Tension Glaucoma
In this variation, the optic nerve becomes damaged even though your eye pressure is within the normal range. The exact cause is unknown, but it may be linked to a sensitive optic nerve or poor blood flow.
Symptoms:
- Similar to open-angle glaucoma.
- Gradual loss of peripheral vision.
- Often detected only during a comprehensive eye exam looking at the optic nerve head.
4. Secondary Glaucoma
This occurs as a result of another condition, such as inflammation in the eye, cataracts, or diabetes. According to Diabetes UK, having diabetes significantly increases your risk of developing glaucoma, alongside diabetic retinopathy.
Comparison of Glaucoma Types
Understanding the urgency of different symptoms is vital. Use the table below to differentiate between the primary presentations.
| Feature | Open-Angle Glaucoma | Acute Angle-Closure Glaucoma | Normal-Tension Glaucoma |
|---|---|---|---|
| Onset Speed | Very slow and gradual over years. | Sudden and rapid (hours). | Slow and gradual. |
| Primary Symptom | Loss of peripheral vision (side vision). | Intense eye pain and headache. | Blind spots in vision. |
| Pain Level | Usually painless. | Severe, debilitating pain. | Painless. |
| Visual Effects | Tunnel vision (late stage). | Haloes around lights, sudden blur. | Vision loss in patches. |
| Urgency | Requires regular monitoring and drops. | Medical Emergency (999 or A&E). | Requires monitoring and lifestyle changes. |
Risk Factors: Are You Vulnerable?
Anyone can develop glaucoma, but certain groups are at higher risk. If you fall into these categories, you should be vigilant about booking your eye tests, ideally once a year or as advised by your optometrist.
Key risk factors include:
- Age: Risk increases significantly as you get older, particularly for those over 60.
- Ethnicity: People of African, Caribbean, or Asian origin are at higher risk and may develop the condition at a younger age. Glaucoma UK provides specific guidance on how ethnicity influences risk profiles.
- Family History: If a parent or sibling has glaucoma, your risk increases. Genetics play a substantial role.
- Medical Conditions: Diabetes, heart disease, and high blood pressure can contribute to eye health issues.
- Corneal Thickness: People with thinner corneas may be at increased risk.
Tips for Protecting Your Vision
While you cannot prevent glaucoma entirely, early detection is the closest thing to a cure. Managing the condition effectively stops it from worsening.
Prioritise Regular Eye Exams
The most effective tool against vision loss is the comprehensive eye exam. This is not just a vision check; it is a health check. Optometrists use tonometry (the ‘puff of air’ test) to measure pressure and ophthalmoscopy to inspect the optic nerve.
Leading bodies like The College of Optometrists recommend regular intervals for testing based on your age and risk profile.
Exercise Safely
Moderate, regular exercise may help lower eye pressure in some cases. However, be cautious with exercises that involve inverting your head (like certain yoga positions), as this can increase intraocular pressure.
Protect Your Eyes
Serious eye injuries can lead to secondary glaucoma. Always wear protective eyewear when using power tools or playing high-speed racket sports.
Adhere to Treatment Plans
If you are diagnosed, you will likely be prescribed eye drops to lower your pressure. It is crucial to use them exactly as prescribed, even if you have no symptoms. Moorfields Eye Hospital notes that consistency is key to preventing further damage.
Frequently Asked Questions
Can glaucoma be cured?
Currently, there is no cure for glaucoma, and vision lost cannot be restored. However, treatment can effectively halt the progression of the disease. Treatments range from daily eye drops to laser therapy and surgery.
Does high eye pressure mean I have glaucoma?
Not necessarily. You can have high eye pressure (ocular hypertension) without optic nerve damage. However, it puts you at a much higher risk, so close monitoring is essential.
Can I still drive if I have glaucoma?
Yes, usually, provided your vision meets the legal standards. However, you must inform the DVLA. GOV.UK outlines the specific driving standards required for those with visual impairments.
What lifestyle changes help?
Eating a balanced diet rich in leafy greens and coloured fruits can support overall eye health. Additionally, stopping smoking is highly beneficial, as smoking restricts blood flow to the optic nerve.
The Bottom Line
Glaucoma is a formidable condition because of its stealthy nature. The symptoms of glaucoma—particularly the open-angle variety—often go unnoticed until it is too late.
However, a diagnosis is not a guarantee of blindness. With modern medicine, laser treatments, and early intervention, most people with glaucoma retain useful sight for life. The key is vigilance.
Do not wait for your vision to blur or for haloes to appear around lights. If you are over 40, have a family history of eye disease, or have not had an eye test in the last two years, book an appointment today.
Organisations like the RNIB offer incredible support for those navigating a new diagnosis, proving that you do not have to face this journey alone. Prioritise your eyes; they are the window to your world.
