In plain English
Hearing loss is the single largest modifiable risk factor for dementia identified by the 2024 Lancet Commission. Treating hearing loss with hearing aids meaningfully reduces dementia incidence. Vision impairment is similarly important.
The evidence
The 2024 Lancet Commission estimates that addressing hearing loss could prevent or delay around 7 per cent of all dementia cases worldwide, the largest single modifiable contribution. Mechanisms include reduced cognitive stimulation, increased cognitive load to compensate, and social withdrawal driven by communication difficulty.
Vision impairment is similarly important; the Lancet Commission's 2024 update added vision impairment as the 14th modifiable risk factor.
Hearing loss in older adults
Age-related hearing loss is extremely common: around 40 per cent of adults over 65 have some hearing loss, and around 70 per cent of those over 80. Most is high-frequency loss, affecting speech understanding particularly in noisy environments. People often adapt gradually and may not recognise the loss themselves.
Signs that hearing should be tested:
- Needing the TV louder than others find comfortable;
- Asking people to repeat themselves;
- Difficulty in restaurants or group conversation;
- Withdrawal from social settings;
- Trouble on the phone;
- Tinnitus.
NHS hearing services
NHS hearing aids are free. Access varies by area:
- In England, GP referral to an audiology service, or direct access in some areas;
- In Scotland, Wales and Northern Ireland, similar pathways with regional variation;
- Hearing aids fitted, with follow-up, batteries and repairs free;
- Waiting times typically 6 to 16 weeks.
Modern NHS hearing aids are digital, programmable, and increasingly Bluetooth-enabled.
Private hearing services
High-street providers (Specsavers, Boots Hearingcare, Hidden Hearing, Amplifon) offer free hearing tests and a range of paid hearing aid options. Costs vary widely (£400 to £4,000 per ear depending on technology). Some are over-the-counter; others require fitting and follow-up.
Wearing hearing aids
Hearing aids work best when worn consistently. The brain adapts over weeks to amplified sound; brief or occasional use does not allow this. New users should aim for several hours daily, increasing over time. Most major adjustments to fit and programming happen in the first 3 months.
Vision in older adults
Common vision problems:
- Cataracts: lens cloudiness; treatable with surgery;
- Age-related macular degeneration: central vision loss; some treatments available;
- Glaucoma: pressure damage to the optic nerve; treatable with drops or surgery;
- Diabetic retinopathy: managed through glucose control and ophthalmology;
- Refractive error: corrected with glasses.
Vision affects cognition in two ways: directly (reduced sensory input to the brain), and indirectly (reduced engagement, reading, social contact, exercise). Treating reversible vision loss is one of the more impactful interventions.
NHS eye care
Sight tests are free for adults aged 60 and over (and for some other groups) in England, Wales and Scotland. Hospital eye services treat cataracts, AMD, glaucoma and other conditions. Cataract surgery is one of the most successful operations in modern medicine.
In dementia
Treating hearing loss and vision impairment matters at every stage of dementia. In moderate to severe dementia, the person may resist hearing aids or glasses or lose them frequently. Practical tips:
- Establish daily routine (aids on with breakfast, off with bedtime);
- Use clip-on attachments to clothing;
- Keep spare batteries;
- Bluetooth aids can stream from a phone or TV, simplifying use;
- Cataract surgery is often well-tolerated and can substantially improve quality of life.
Frequently asked questions
Will a hearing aid prevent dementia?
Wearing a hearing aid is associated with a measurable reduction in dementia incidence in trials and large cohort studies. It does not eliminate risk but is one of the more impactful single interventions.
Are NHS hearing aids as good as private?
Modern NHS hearing aids are digital, programmable and effective for most people. Private aids may offer additional features (smaller form, advanced noise processing, premium Bluetooth) that some people value. The NHS option is appropriate as a first step.
How long does it take to get used to hearing aids?
Most people adapt within 4 to 8 weeks of regular wearing. The brain re-learns to process amplified sound; brief or occasional use prevents this.
Should I have cataract surgery if I have dementia?
Often yes. Cataract surgery is generally well-tolerated, produces meaningful improvement in vision and quality of life, and reduces falls. Discuss the anaesthetic and post-operative care with your ophthalmologist.
Is age-related macular degeneration treatable?
Wet AMD has effective injection treatments. Dry AMD has no specific treatment but lifestyle factors (smoking, diet, supplements in some cases) modify progression.
References
- Livingston G et al. Dementia prevention, intervention and care: 2024 Lancet Commission.
- Lin FR et al. Effect of hearing intervention versus health education control on cognitive decline. JAMA 2023 (ACHIEVE trial).
- Royal National Institute for Deaf People (RNID).
- Royal National Institute of Blind People (RNIB).