The short version
Two conditions cause most avoidable sight loss in older adults in the UK, they behave in opposite ways, and the useful action for each is different.
| Glaucoma | Macular degeneration | |
|---|---|---|
| Takes | Peripheral vision first | Central vision first |
| You notice | Nothing, until it is late | Distortion, then a blur in the middle |
| Reversible? | No. Damage is permanent | No, but wet AMD can be halted |
| The action | Get tested — there is no self-check | Act fast on new distortion |
| Read | Glaucoma | Macular degeneration |
Four things worth doing
Book a sight test, and find out if it is free
There is no national glaucoma screening programme, so a routine sight test is the detection route for both conditions. Scotland: free for everyone. England, Wales and Northern Ireland run a list, and these are the ones people miss:
- 60 and over
- Aged 40 or over with a parent, sibling or child diagnosed with glaucoma
- Diagnosed diabetes or glaucoma, or told by an ophthalmologist you are at risk of glaucoma
- Under 16, or 16–18 in full-time education
- Registered sight-impaired, or eligible for a complex-lens voucher
- On Income Support, income-based JSA, income-related ESA, Pension Credit Guarantee, Universal Credit within the earnings limit, or holding an NHS tax credit exemption or HC2 certificate
Ask your relatives, and tell them
Family history is the strongest single risk flag for glaucoma and it is the one piece of information that is free to obtain. If you have it, so do your children.
Cover one eye, then the other, now and again
Both conditions are routinely missed in one eye because the other compensates completely. Ten seconds at a doorframe or a window will do it: look for lines that bend, or a patch that is missing.
Do not smoke
The largest modifiable risk factor for macular degeneration by a wide margin, and it is on the list for almost everything else on this site.
Two urgent patterns
Sudden severe eye pain with haloes around lights, a red eye, and nausea — possible acute angle-closure glaucoma. Same-day emergency eye care. It is sometimes mistaken for migraine or a stomach upset and the eye is never examined.
New distortion — straight lines looking bent or wavy — possible wet macular degeneration. Same week, and treat it as same day if it is worsening. Injections protect the sight you still have; they do not return what has gone.
Over 50, with sudden visual loss alongside a new headache at the temple, scalp tenderness, or jaw ache that comes on while chewing — possible giant cell arteritis. Same day, urgently. This one is on the list for a specific reason: untreated, it threatens the other eye within days, and the treatment that prevents that is started on suspicion rather than after a test.
What is being sold, and what it is worth
Two things are currently promoted heavily for glaucoma, and this site grades both rather than dismissing them.
- High-dose nicotinamide (vitamin B3). Real mechanism, striking mouse data, two small positive human trials on research endpoints — and a joint position statement from two specialty societies saying those endpoints do not reliably translate into anything a patient notices. The phase 3 trial reports in late 2027. Graded Emerging. The doses involved are pharmacological, not nutritional, and need liver monitoring.
- Slow-paced breathing. One randomised trial found about 2 mmHg of pressure reduction added to standard treatment. Unblindable, on a surrogate endpoint, and modest — but free and harmless, so there is no reason to talk anyone out of it alongside their treatment.
Both are covered in full in what is being sold for glaucoma. Neither replaces pressure-lowering treatment, and the one genuinely important thing to know about UK glaucoma care is on the glaucoma page: since 2022, NICE has recommended laser rather than lifelong drops as a first-line option, on the strength of a British trial. A great deal of published advice has not caught up.