We regularly carry out home eye tests for patients living with dementia.
Dementia is not a disease itself, but a term used to describe a group of symptoms that affect memory, thinking, and everyday functioning.
These symptoms are most commonly associated with Alzheimer’s disease, which is the most common cause of dementia, but dementia can also be caused by other neurological conditions.
The symptoms of dementia vary depending on which part of the brain is affected and the condition causing it.
In addition to memory problems, dementia can affect speech, mood, personality, and visual processing.
Did you know that one of the lesser-known symptoms of dementia is changes to vision?
How Does Dementia Affect Vision?
Dementia can affect vision because both the eyes and the brain rely on complex nerve pathways.
While the eyes themselves may remain healthy, dementia can interfere with how the brain interprets what the eyes are seeing.
This means that a person with dementia may have good visual acuity on an eye test, but still struggle to understand, recognise, or respond to visual information.
This is sometimes described as a problem with visual processing rather than a problem with the eyes themselves.
Does Dementia Affect Eyesight?
Yes, dementia can affect eyesight and the way a person experiences their vision. However, it is important to understand that not every vision problem experienced by someone with dementia is caused directly by dementia.
People with dementia can develop common age-related eye conditions such as cataracts, glaucoma and age-related macular degeneration. These conditions can cause genuine changes to eyesight and may be treatable.
Dementia can also affect the way the brain processes visual information. A person may therefore appear to have difficulty seeing even when the eyes themselves are relatively healthy. This is one of the reasons why regular eye tests are particularly important for people living with dementia.
What Type of Dementia Affects Vision?
Different types of dementia can affect vision in different ways.
Alzheimer’s disease can cause problems with visual processing, including difficulties with recognising objects, judging distances and detecting contrast.
Posterior cortical atrophy (PCA) is a less common form of neurodegenerative condition that particularly affects the areas of the brain responsible for processing visual information. People with PCA can experience significant visual difficulties even when their eyes are healthy.
This shows why it is important to consider both eye health and the brain's ability to process visual information when someone with dementia develops changes in their vision.
What Vision Problems Can Dementia Cause?
Dementia can affect more than just how clearly a person sees. It can also affect how they interpret what they are seeing.
Common vision problems associated with dementia can include:
- Difficulty recognising familiar people or objects.
- Problems judging distances and depth.
- Difficulty detecting movement.
- Reduced contrast sensitivity, making objects blend into their surroundings.
- Difficulty identifying certain colours.
- Problems with peripheral vision.
- Difficulty reading or writing.
- Difficulty finding objects that are directly in front of them.
These problems can sometimes be mistaken for memory problems. For example, someone may appear not to recognise an object when the underlying problem is actually their ability to process the visual information. This means that a change in vision should not automatically be assumed to be caused by dementia. An eye examination can help identify whether there is an underlying eye condition that needs treatment.
Here are the Common Causes of Vision Problems in Dementia :
- Eye conditions such as cataracts, macular degeneration and glaucoma.
- Health conditions including stroke and diabetes.
- Normal ageing changes affecting the eyes.
- Dementia-related conditions such as Alzheimer’s disease, Parkinson’s disease and Posterior Cortical Atrophy (PCA) which directly affect visual processing of the brain.
Some dementia patients experience visual problems even when their eyes are healthy.
This is because dementia can affect perception — how the brain makes sense of shapes, depth, movement and contrast — rather than how clearly the eyes can see.
This means that a change in vision should not automatically be assumed to be caused by dementia. An eye examination can help identify whether there is an underlying eye condition that needs treatment.
Common Vision Problems in Alzheimer’s Disease
The following visual difficulties are commonly identified in people with Alzheimer’s disease:
- Reduced ability to detect motion.
- Reduced contrast sensitivity, making objects blend into their background.
- Problems with depth perception and judging distances.
- Difficulty recognising certain colours, particularly blue and purple.
- Reduced peripheral vision (vision around the edges while looking straight ahead).
Signs of Vision Problems in Dementia – What Carers Should Look Out For?
If you are a carer for someone with dementia, vision problems may not always be obvious.
Look out for the following signs:
- Difficulty reading or writing.
- Problems recognising familiar people.
- Struggling with changes in lighting such as bright or dim environments.
- Misplacing objects or forgetting where things are.
- Bumping into furniture or door frames.
- Difficulty reaching for objects like door handles.
- Ongoing visual problems even when wearing glasses.
If you notice a change in someone's vision, it is important not to assume that it is simply part of their dementia. There may be an underlying eye condition that can be diagnosed and treated.
Can Dementia Cause Sight Loss?
Dementia itself does not necessarily mean that a person will lose their sight. However, people living with dementia can develop eye conditions that cause sight loss, particularly as many forms of dementia are more common in older people.
Problems with visual processing can also make it more difficult for someone with dementia to use the vision they have effectively. This is why maintaining good eye health is important. Identifying and treating conditions such as cataracts, glaucoma and macular degeneration can help prevent avoidable sight loss and make it easier for someone with dementia to use their remaining vision.
Why Regular Eye Tests Are Important for Dementia Patients
Regular eye tests are essential for people living with dementia.
They help distinguish between eye health issues and visual processing problems caused by dementia.
Regular eye tests allow changes in vision to be monitored over time.
It is important to inform your optician about any diagnosis of dementia and any changes in behaviour or vision that have been noticed.
Free NHS Home Eye Tests for Dementia Patients
Home Eyecare provides free NHS home eye tests for housebound dementia sufferers aged over 60.
Dementia patients under the age of 60 may also qualify for a free NHS home eye test if they receive certain benefits.
If you or someone you care for is living with dementia and is unable to attend a high street optician, a home eye test ensures they receive professional eye care in a familiar and comfortable environment.
To book a home eye test, contact us today on
01527 529010 to speak to our friendly team.