Dementia and sight loss
People with a dementia may also suffer from sight loss. Find out the causes and signs of dementia-related sight loss.
Causes of sight loss in dementia
Sight loss can be caused by:
- the dementia itself
- normal aging of the eye
- an eye infection, such as cataracts
- another health condition, such as stroke
If you have a dementia, you might have trouble seeing, but still have healthy eyes. These problems are caused by the effects of dementia on the brain.
Dementia conditions that can affect your vision include:
- Lewy body dementia
- Alzheimer’s disease
- posterior cortical atrophy
- vascular dementia
Sight loss is often undiagnosed in people with a dementia because the dementia can mask symptoms of sight loss, or your sight loss could be mistaken for a symptom of dementia.
Signs of dementia-related sight loss
If you have a dementia, consider if you find it hard to:
- read
- recognise people
- cope with bright light, low light or both
- find things
- avoid obstacles
- find food on your plate
- see well with your glasses
Your behaviour may change as a reaction to the sight loss and you:
- become withdrawn or uncommunicative
- are clumsy or fall more
- have visual hallucinations
- need to hold things up close to see them
- feel confused and disorientated
- are startled by noises or people approaching
Charles Bonnet Syndrome
Charles Bonnet Syndrome (CBS) is common among people who have lost their vision from an eye condition.
Its symptoms can sometimes be mistaken for symptoms of a dementia and could exacerbate other symptoms of dementia.
CBS causes people to see things that aren’t there.
These visual hallucinations can be distressing.
They usually last between a year and 18 months, following the loss of sight. After this they become a lot less frequent.
There's no cure for CBS.
It is very important that if someone displays symptoms of CBS that they are investigated to make sure they are not caused by a dementia.
Looking after your sight
If you have a dementia, you should have your sight examined regularly.
In Northern Ireland, the sight test is free for people over the age of 60.
Your local optometrist can advise you about eye health and make sure you wear the correct glasses.
Many will even come to your home or make arrangements to see you at a time that suits you.
If you are a carer for someone with dementia, they may not be able to tell you about changes to their sight.
You should make sure they have regular eye tests.
Living with sight loss
Depending on the cause of your sight loss, there may or may not be medical treatments available.
Your doctor will be able to explain what options are available.
If you are experiencing sight loss, there are things you can do to help, including:
- make sure your glasses prescription is correct and the lenses are clean
- make sure your glasses fit well
- make sure there is good, even lighting in your home to minimise shadows
- plainly decorated walls can be better than patterned walls
- make sure to take your medication, especially eye drops
If you’re caring for someone with dementia, tell them about their environment when you’re guiding them.
It’s important to visit the optometrist regularly if you have dementia.
It will help when visiting the optometrist if you:
- let them know you have dementia
- bring a list of your medication
- have your current glasses with you
- tell them if there is a history of eye problems in your family
Where to find help and support
You can find further information on dementia and support services available at the link below: