Vision loss, dementia and what it could mean for you

More than 1 in 10 people over the age of 50 have uncorrected visual impairment — a sight problem which hasn’t been corrected by wearing glasses, contact lenses, or having surgery or treatment.

Last year, the Lancet Commission found evidence that visual impairment caused by cataracts and diabetic retinopathy were linked to a higher likelihood of developing dementia. But glaucoma and age-related macular degeneration do not appear to be linked to dementia.

Cataracts occur when the lenses of our eyes break down, making our vision unfocused and blurry. Many people will develop cataracts as they age, but surgery can help — by replacing an old lens with a new, clear one.

Diabetic retinopathy is the most common cause of preventable sight loss among people in mid-life. It’s caused by diabetes, itself a risk factor for dementia. It damages the retina — the part of the eye which turns light into electrical signals for our brains to process.

Not wearing glasses or lenses when you need them also appears to increase dementia risk. So if you’re prescribed these, it’s important to use them as directed.

Research is ongoing to unravel the relationship between visual impairment and increased dementia risk. At the moment there are three main schools of thought as to what the link may be:

• Illnesses like diabetes that can cause visual impairment also increase dementia risk themselves.
• Damage to our senses, like vision loss, can result in our brains receiving less stimulation. And this can make us more vulnerable to diseases like Alzheimer’s.
• Diseases like Alzheimer’s damage our brains. But they could also cause changes to our eyes, and it’s this that leads to visual impairment.

What steps can I take to look after my eyes and vision?

Always have regular check ups with your optician. And if you’re prescribed glasses or lenses, use them as directed. Also, if you have concerns about cataracts, diabetes or diabetic retinopathy, speak with your GP as soon as possible.

Looking after your overall health could also help to protect your eyes. Which means:

• Eating a balanced diet, with a variety of fruits and vegetables.
• Maintaining a healthy weight and blood pressure.
• Being physically active every day.
• Stopping smoking and drinking alcohol in line with government recommendations (no more than 14 units of alcohol a week, spread across several days).

Our incredible supporter, Simon, knows just how important it is to look after his brain health. Simon’s dad, Alan, was diagnosed with Alzheimer’s disease in 2009. Alan sadly passed away in 2020.

To help reduce his risk of dementia, Simon keeps connected to others by making sure he wears his glasses and gets his vision checked regularly.

“I’ve worn glasses since I was 14. I first noticed that I needed glasses either when playing sport and the speed of the ball started affecting me, or when reading from a distance at school became difficult. That was when my mum took me to see the optician. Just recently I made a point of encouraging my son to get his eyes tested, so it’s all coming back around!

“I have my eyes tested a minimum of every two years. Over time I’ve moved from being short sighted to needing varifocals, but there isn’t always a change.

“And just because I might have deteriorating eyesight doesn’t necessarily mean I’m going to get dementia – it just means that by attending regular optician check-ups, I’m giving myself a better chance of reducing my risk of dementia. Even if it reduces your chances by a small percent, it’s all the little things we can do that help us feel a greater sense of calm and control.

“When people talk about brain health, any sensible connection is worth considering. We’ve long known that eating whole foods, fruit and veg, as well as exercising regularly help us as we age; the fact that looking after my eyesight too can only be a good thing.”

If you have a question about dementia risk, diagnosis or our research, you can call our Dementia Research Infoline on 0300 111 5 111 (lines are open from 9am – 5pm, Mon-Fri) or email us at infoline@alzheimersresearchuk.org