Introduction
Glaucoma is a group of eye diseases that damage the optic nerve—the cable that carries visual signals from the eye to the brain. Raised pressure inside the eye (intraocular pressure) is a major risk factor, but glaucoma can also occur when pressure readings are in the “normal” range (normal-tension glaucoma).
Open-angle glaucoma is the most common form. It usually progresses slowly and painlessly, often without noticeable symptoms until peripheral (side) vision is already reduced. Acute angle-closure glaucoma is less common but is an emergency: sudden eye pain, headache, halos, nausea, and blurred vision need urgent care.
Damage to the optic nerve cannot be reversed, but early detection and pressure-lowering treatment can slow or stop further vision loss. Regular comprehensive eye exams are the only reliable way to catch silent disease early.
This page is general education. Diagnosis and treatment plans come from an eye-care specialist (ophthalmologist or optometrist as appropriate in your setting).
Overview
Glaucoma is not the same as high eye pressure alone (ocular hypertension). Glaucoma means optic nerve damage with characteristic vision field loss; high pressure without nerve damage is monitored differently.
Types differ by drainage-angle anatomy and speed of onset. Primary open-angle glaucoma drains poorly despite an open angle; angle-closure forms involve sudden or intermittent blockage of the drainage angle.
Treatment aims to lower eye pressure with drops, laser, or surgery and to monitor optic nerve and visual fields lifelong.
- Optic nerve disease—often linked to eye-pressure imbalance
- Open-angle: slow, often symptom-free until late
- Acute angle-closure: painful emergency with rapid vision threat
- Risk rises with age, family history, ethnicity, diabetes, and steroid use
- Diagnosis needs pressure, optic nerve, and visual field assessment—not one test
- Vision already lost cannot be restored; further loss is often preventable
What happens in the body
Aqueous fluid is produced inside the eye and normally drains through the trabecular meshwork. When drainage is impaired, pressure can rise and stress the optic nerve head, killing nerve fibres over time. Peripheral vision is typically affected first.
In angle-closure attacks, the iris blocks the drainage angle abruptly, pressure spikes, and symptoms appear suddenly. Some people have optic nerve vulnerability even at average pressures.
- Impaired aqueous drainage → pressure stress on the optic nerve
- Open-angle: gradual fibre loss; closed-angle: sudden blockage possible
- Normal-tension glaucoma: nerve damage despite “normal” pressure readings
- Steroids, trauma, and prior eye surgery can contribute to secondary glaucoma
Signs and symptoms
Symptoms depend on type. Open-angle disease is often silent; acute angle-closure is dramatic:
- Open-angle: gradual loss of peripheral vision
- Open-angle: patchy blind spots in side or central vision
- Open-angle: tunnel vision in advanced stages
- Acute angle-closure: severe eye pain and headache
- Acute angle-closure: red eye, blurred vision, halos around lights
- Acute angle-closure: nausea and vomiting with eye symptoms
- Any sudden vision change, eye pressure sensation, or rapid vision loss
- Often no early pain in the most common chronic forms
Causes and risk factors
Optic nerve damage has many contributors. Common risk factors include:
- Elevated intraocular pressure from impaired fluid drainage
- Age over 40, with risk rising further after 60
- Family history of glaucoma
- African, Black, or Hispanic ancestry (higher risk for some forms)
- Diabetes, high blood pressure, heart disease, or sickle cell disease
- Myopia or hyperopia; prior eye injury or eye surgery
- Long-term corticosteroid use, including steroid eye drops
- Hormonal factors such as early bilateral oophorectomy in some studies
Diagnosis and evaluation
No single test diagnoses glaucoma. A full assessment usually includes:
- Intraocular pressure measurement (tonometry)
- Optic nerve examination, often with imaging over time
- Visual field (perimetry) testing for peripheral vision loss
- Corneal thickness measurement to interpret pressure readings
- Drainage angle examination (gonioscopy) to classify open- vs closed-angle disease
- Optical imaging of the nerve fibre layer when available
- Regular follow-up to track progression and treatment response
Treatment and management
Existing nerve damage cannot be undone. Treatment lowers pressure to protect remaining vision. Do not stop drops without specialist advice:
- Prescription eye drops (prostaglandins, beta blockers, alpha agonists, carbonic anhydrase inhibitors, miotics) as first-line for many patients
- Oral carbonic anhydrase inhibitors short-term when drops are not enough
- Laser trabeculoplasty to improve drainage in open-angle disease
- Laser procedures for acute angle-closure to open the drainage pathway urgently
- Filtering surgery, drainage tube implants, or other surgical options when pressure remains uncontrolled
- Urgent combined medical and laser/surgical care for acute angle-closure attacks
- Lifelong monitoring even when pressure seems controlled
Prevention, self-care, and lifestyle
Not every condition is fully preventable, but the steps below may lower risk or recurrence:
- Glaucoma itself is not always preventable, but vision loss often is—through early detection
- Comprehensive eye exams every 1–2 years from age 40, or earlier/more often with risk factors
- Control diabetes, blood pressure, and heart disease
- Protective eyewear to reduce injury-related secondary glaucoma
- Use steroids only as prescribed; tell your eye doctor about all medicines
- Balanced diet, regular activity, and not smoking support overall eye health
- Do not ignore mild or temporary vision changes
Possible complications
Delay, missed care, or unsafe self-medication can raise the chance of complications in some cases:
- Progressive peripheral vision loss and tunnel vision
- Irreversible blindness if untreated
- Reduced independence with driving, reading, and navigation
- Higher vulnerability after eye injury or some eye surgeries
- Anxiety and reduced confidence related to fear of blindness
- Side effects of long-term drops or surgical complications in some patients
When to see a doctor or seek emergency care
Seek prompt medical advice or emergency care if any of the following apply—it is safer not to wait and see:
- Sudden severe eye pain, headache, red eye, halos, or vomiting with visual symptoms—emergency
- Rapid partial or complete vision loss
- New blurred vision or halos, especially with eye redness
- Vision changes after eye injury or recent eye surgery
- Age over 40, family history, diabetes, or other risk factors—schedule routine screening
- Any unexplained gradual side-vision loss
- Inability to tolerate prescribed drops—contact the clinic rather than stopping silently
Living with the condition
Glaucoma is a chronic condition. Taking drops exactly as prescribed, attending follow-ups, and managing blood pressure and diabetes are the core daily habits that protect remaining sight.
Many people continue work and driving when disease is detected early and pressure is controlled. Ask your specialist about visual standards for driving in your region.
Bring a full medication list to visits. Avoid self-medicating with steroid drops. Low-vision support and counselling help if fields are already narrowed.
Frequently asked questions
What is glaucoma in simple terms?
It is an eye disease that damages the optic nerve, often linked to fluid pressure inside the eye. Early stages are frequently silent, so regular eye exams matter.
Is glaucoma curable?
No permanent cure exists, but treatment can control eye pressure and slow or prevent further vision loss when started in time.
Are glaucoma symptoms painful?
The common open-angle form is usually painless. Acute angle-closure glaucoma causes severe eye pain, headache, nausea, and visual disturbance and needs emergency care.
Can glaucoma cause blindness?
Yes, untreated glaucoma can cause permanent blindness. Early detection and consistent treatment greatly reduce that risk.
How often should I get eye checks?
Adults over 40 often need exams every 1–2 years; higher-risk people or those with vision changes may need more frequent testing as advised by their eye specialist.
Can children get glaucoma?
Yes, though it is uncommon. Infants and children with suspicious signs need specialist assessment so vision development is protected.
Do eye drops cure glaucoma?
Drops do not cure glaucoma, but they are highly effective at lowering pressure and protecting remaining vision when used as prescribed.
Will I need lifelong treatment?
Most people need ongoing treatment and monitoring. Stopping therapy without advice can allow pressure—and nerve damage—to worsen.
Is surgery always required?
No. Many people are managed with drops or laser. Surgery is considered when pressure remains too high or disease progresses despite other measures.
Can vision improve after treatment?
Treatment aims to prevent further loss. Vision already damaged by glaucoma usually cannot be restored.
Important caution
This article is general health education in English. It is not a substitute for eye-specialist care.
Sudden painful red eye with visual change is an emergency—seek care immediately.
Caught early, glaucoma is often controllable so many people keep useful vision for life.