--- title: "Glaucoma | Eye Health Guide" description: "Open-angle versus angle-closure glaucoma, who should skip this page, tests, drops laser and surgery, and driving. Clinically reviewed." url: https://eyehealthguide.org/conditions/glaucoma/ source: Eye Health Guide licence: "General information only. Cite the URL and the named medical reviewer." --- Condition # Glaucoma Medical reviewer [Mr Mohamed Mohyudin](https://eyehealthguide.org/reviewers/mohamed-mohyudin/)· Last recorded site review July 6, 2026 ### About this review This page inherits the site’s previous review record. A separate, current article sign-off has not yet been recorded. [How review works](https://eyehealthguide.org/reviewers/) · [Official biography & credentials](https://mohamedmohyudin.co.uk/author/mohamed-mohyudin/) Quick answer Glaucoma is a group of diseases that damage the optic nerve, often related to pressure inside the eye. The common open-angle type has no early symptoms — side vision fades unnoticed. Acute angle-closure is a painful emergency. Treatment lowers pressure to slow further loss; it cannot restore sight already gone. This page is not for sudden painful red eye with halos and nausea — that needs emergency care, not a routine booking. References for this section: NHS — Glaucoma ↗National Eye Institute - Glaucoma ↗ ### On this page ⌄ 1. Visual guide 2. Your next step 3. What is glaucoma — and who should skip this page? 4. How do open-angle and angle-closure glaucoma differ? 5. Who is at higher risk — and what tests actually happen? 6. What treatments exist — and who should not expect a cure? 7. Can I drive and work with glaucoma? 8. When is glaucoma an emergency? 9. Related conditions 10. Related symptoms 11. Practical guides 12. Treatments & Surgery 13. Frequently asked questions Understand it visually ## Explore the diagram **How the eye works** The optic nerve carries visual information from the retina to the brain. Eye examinations assess both this nerve and eye pressure. **What changes** Glaucoma damages the optic nerve. It may develop without early symptoms and can occur even when eye pressure is within the usual range. 1. Lens 2. Retina 3. Optic nerve Simplified educational diagram. It does not show what every person sees or replace an eye examination. Sources for this information ## What is glaucoma — and who should skip this page? Glaucoma damages the optic nerve that carries vision to the brain. Eye pressure is a major risk factor, but some people develop glaucoma with pressure in the statistically normal range (normal-tension glaucoma). Skip this page and seek emergency care if you have sudden severe eye pain, headache, nausea, rainbow halos and blurred vision in one eye — that pattern can be acute angle-closure, not a leisurely read. Open-angle glaucoma is slow and usually painless. People often notice it only when side vision is already reduced, or when an optometrist finds a suspicious nerve or field. That is why regular tests matter more than waiting for a symptom. We do not publish a single global “success rate” for drops or surgery. Published figures vary by disease type, how late it is found, and how “success” is defined. Lost nerve fibres do not grow back. [Ocular hypertension](https://eyehealthguide.org/conditions/ocular-hypertension/)[Using glaucoma drops](https://eyehealthguide.org/eye-care/using-glaucoma-drops/) References for this section: NHS — Glaucoma ↗National Eye Institute - Glaucoma ↗ ## How do open-angle and angle-closure glaucoma differ? The names describe the drainage angle where fluid leaves the eye. In primary open-angle glaucoma the angle looks open but drainage is inefficient over years. In angle-closure the iris crowds or blocks that drain, so pressure can rise fast. East Asian heritage raises angle-closure risk; African-Caribbean and Hispanic heritage raises open-angle risk. Family history matters for both. These are risk markers, not a diagnosis. Two patterns — not a diagnosis from this table | Pattern | Typical pace | Typical warning | Usual first steps after diagnosis | | --- | --- | --- | --- | | Primary open-angle | Years, often silent | None until side vision is damaged | Drops, selective laser, lifelong monitoring | | Acute angle-closure | Hours | Pain, nausea, halos, red eye, blur | Emergency pressure-lowering, then laser iridotomy | | Normal-tension | Years | Often none; nerve looks damaged despite ‘normal’ pressure | Lower pressure further; investigate other causes if needed | References for this section: NHS — Glaucoma ↗National Eye Institute - Glaucoma ↗ ## Who is at higher risk — and what tests actually happen? Risk rises with age over 40, a first-degree relative with glaucoma, high eye pressure, short-sightedness for open-angle types, long-sightedness for angle-closure types, diabetes, long-term steroid use, and previous eye injury. Adults should have regular eye tests that can include pressure, optic-nerve assessment and visual fields when indicated. Diagnosis is not one high pressure reading. Clinicians repeat pressure, look at the nerve (often with OCT), map the visual field, and may use gonioscopy to see the drainage angle. One isolated number does not equal glaucoma. If you take steroid tablets, inhalers, creams around the eyes or steroid drops, say so. Steroids can raise pressure in susceptible people. - Tonometry — measures eye pressure - Optic nerve examination, often with OCT imaging - Visual field test — maps side vision - Gonioscopy — inspects the drainage angle - Pachymetry — corneal thickness can change how pressure is interpreted References for this section: NHS — Glaucoma ↗National Eye Institute - Glaucoma ↗ ## What treatments exist — and who should not expect a cure? Treatment lowers pressure to slow further damage. It does not reverse existing field loss. Most people start with daily drops. Selective laser trabeculoplasty (SLT) can improve drainage in open-angle disease. Laser iridotomy is used when the angle is at risk of closing. Surgery (trabeculectomy or MIGS devices) is for when drops and laser are not enough. Missed drops allow pressure spikes. If a drop stings, blurs, or changes breathing or heart rate, tell the prescriber — alternatives exist. Do not stop a drop because an internet list ranked it ‘mild’. Tell every doctor and anaesthetist you use glaucoma medicines. Some drugs interact with eye pressure or with surgery plans. [Glaucoma treatment pathway](https://eyehealthguide.org/treatments/glaucoma-treatment/)[Glaucoma laser surgery](https://eyehealthguide.org/treatments/glaucoma-laser-surgery/) References for this section: NHS — Glaucoma ↗National Eye Institute - Glaucoma ↗ ## Can I drive and work with glaucoma? Driving depends on the legal visual standard where you live — including visual fields, not only the letter chart. In the UK, glaucoma field loss can mean you must notify the licensing agency even if you still read the number plate. We do not list every country’s rule; ask your clinic and the local licensing body. Night driving and crowded visual tasks get harder when side vision shrinks. That is a safety verdict, not a moral one. Occupational driving and work at heights may have extra rules. ## When is glaucoma an emergency? Acute angle-closure is an emergency: severe pain, headache, nausea or vomiting, halos, a red eye and sudden blur. Same-day care also matters for sudden vision loss, a dark curtain, or a painful red eye after surgery. Open-angle glaucoma itself is not an excuse to ignore those patterns. [What does sudden vision loss mean?](https://eyehealthguide.org/answers/what-does-sudden-vision-loss-mean/)[Red eye](https://eyehealthguide.org/symptoms/red-eye/)[Support cataract charity (optional donate)](https://eyehealthguide.org/support/) ## Related conditions ## Related symptoms ## Practical guides ## Treatments & Surgery ## Frequently asked questions ### Does glaucoma have early symptoms? Open-angle glaucoma usually has none until side vision is damaged. Sudden pain, headache, halos and blur suggest acute angle-closure — an emergency. ### Can glaucoma be cured? No. Treatment can usually slow or stop further loss. Earlier detection protects more remaining sight. ### How often should I use glaucoma drops? Exactly as prescribed. Missed doses allow pressure spikes. The using glaucoma drops guide covers technique, including waiting between different bottles. ### Is glaucoma hereditary? Family history increases risk. Close adult relatives of people with glaucoma should have regular eye tests, not a one-off ‘quick look’. ### What is normal-tension glaucoma? Optic nerve damage with eye pressure in the statistically normal range. Treatment still aims to lower pressure further after other causes are considered. ### Will cannabis or eye ‘exercises’ treat glaucoma? No reliable public guidance supports either as a substitute for prescribed pressure-lowering. Do not stop drops for an unproven product. Optional — donate ## Want to fund sight-restoring surgery? Eye Health Guide does not take donations. If you want to give, World Aid Network funds cataract and other sight-restoring operations through locally licensed ophthalmologists in Pakistan, Indonesia and Malaysia. [Donate at World Aid Network](https://worldaidnetwork.org/donate)[World Aid Network eye health](https://worldaidnetwork.org/eye-health)[Their page on this condition](https://worldaidnetwork.org/eye-health/glaucoma)[How this site relates to the charity](https://eyehealthguide.org/support/) Eye Health Guide and World Aid Network are related public-interest projects and share a medical reviewer. Donations go to World Aid Network. This website does not take a cut, and giving is never required to read a page. Your next step ## Take this to your appointment Keep your planned pressure, optic-nerve and visual-field checks, even if you see well. If you have been prescribed drops, use them as directed and discuss any difficulty with your eye-care team. - What type of glaucoma do I have, and is it changing? - What pressure range are we aiming for in each eye? - Can you watch me use my drops and check the technique? - When are my next nerve scans and visual-field tests? Sudden loss of sight, severe eye pain or a dark curtain across vision needs immediate assessment. Do not wait to complete a worksheet. ## Sources for this information These references support the information on this page. Follow the linked source for its full context. - [NHS — Glaucoma](https://www.nhs.uk/conditions/glaucoma/) - [National Eye Institute - Glaucoma](https://www.nei.nih.gov/eye-health-information/eye-conditions-and-diseases/glaucoma)