Sudden severe eye pain, a red eye, blurred vision or nausea with eye symptoms requires immediate medical attention. An acute angle-closure attack is one possible cause and can threaten sight. Do not wait for an ordinary appointment or try a different person's eye drops. 1
Common slow-developing glaucoma can have no noticeable early symptoms. Being able to read, having no pain or getting one normal eye-pressure reading cannot rule out optic-nerve damage. An eye examination is needed to check for glaucoma. 23
What does glaucoma damage?
Glaucoma is a group of conditions that damage the optic nerve, which carries visual information to the brain. Gradual loss may affect peripheral vision before an obvious problem is noticed. Eye examination matters even when a person does not feel unwell. 2
Types of glaucoma and their symptoms
| Pattern | What may happen | What you need to know |
|---|---|---|
| Common open-angle disease | Little or no early awareness; gradual visual-field change | Symptoms cannot replace examination |
| Acute angle closure | Sudden painful red eye, blur or nausea | An eye emergency needs immediate assessment |
| Glaucoma with pressure in a usual range | Nerve damage despite a non-high reading | Pressure alone is not the diagnosis |
Some angle-closure disease also develops more slowly. The categories explain why both “glaucoma always hurts” and “glaucoma never has symptoms” are misleading. 13
What are the first signs of glaucoma?
There may be none that a person can reliably notice in common early disease. Later, changes in the visual field can become apparent, but waiting for noticeable symptoms can mean waiting until damage has occurred. An eye professional assesses risk and determines the appropriate examination and follow-up. 2
Home vision checks and online quizzes cannot rule out glaucoma or replace an eye examination.
Is high eye pressure the same as glaucoma?
No. Raised pressure increases risk, but some people with high pressure do not develop glaucoma and some people with glaucoma do not have high pressure. Assessment includes the optic nerve and visual function, not one isolated number. 3
Arm-cuff blood pressure is also a different measurement from pressure inside the eye. A normal home blood-pressure result cannot answer whether an eye is healthy.
What does the examination look for?
An eye assessment may include dilation, inspection of the optic nerve and visual-field testing. Findings and risk factors determine what further tests or monitoring are needed. Ask whether the result establishes existing damage, a risk requiring monitoring, or an uncertain finding. 2
Bring the names of your eye drops and any previous eye reports. If you are unsure whether you have been checked for glaucoma, ask your eye-care professional.
What can treatment accomplish?
Treatment aims to reduce further damage. Options can include medicines, laser or surgery; a prescribed drop may reduce fluid production or improve drainage. Feeling normal is not a reason to stop the prescribed plan. 24
Existing optic-nerve damage is not reversed by conventional glaucoma treatment. A promise to restore all vision should not be confused with evidence that a treatment reduces future progression. Ask your eye-care professional what benefit to expect from your treatment. 2
Glaucoma versus cataracts
A cataract affects the eye's lens, while glaucoma affects the optic nerve. Lens replacement does not repair nerve damage, and both problems can coexist. The cataracts versus glaucoma comparison explains why an operation and ongoing glaucoma care may address different needs. 53
What should you bring to follow-up?
Bring your medicine list and tell your eye-care professional about missed doses, side effects or difficulty using drops. Do not adjust the dose yourself. Get urgent help for a new painful red eye or sudden loss of vision. 14
For a routine visit, the appointment worksheet has space for your medicines and questions. Do not delay emergency care to fill it in.
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