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 visual difficulties 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 are having difficulty with;
- recognising people
- coping with bright light, low light or both
- finding things
- avoiding obstacles
- locating food on your plate
- seeing well with your current glasses
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 the dementia.
You might find your behaviour changes as a reaction to the sight loss. Some people with dementia find they;
- become withdrawn or uncommunicative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 is currently 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 site 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 at the right time. 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. It’s very important you make sure the person with dementia has regular eye tests.
Coping 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 you cope, including:
- make sure your glasses prescription is current and 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
- having plain backgrounds, such as walls, can be more helpful than patterned
- if you’re caring for someone with dementia, give them information about their environment when you’re guiding them
- make sure any medication is taken, especially eye drops
It’s especially important that you 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 more information and support services from the following organisations, see also ‘more useful links section’:
The Public Health Agency has also produced a range of information to help support people with a dementia, their families and friends.
This information includes the following publications:
- Ten common signs of dementia
- Early stages of dementia
- Communicating effectively with a person living with dementia
- Are you worried about dementia?
Dementia apps library
The ‘Apps4Dementia’ library is a digital service which groups together safe, trusted apps to provide information and guidance on the condition.
There a number of apps that offer support, self-care of symptoms and enable users to carry on with their day-to-day activities for as long as possible.