It is believed that 60% or more of people with any form of dementia have impaired vision. It is important to understand what this means.
Often when I suggest to carers that the person with dementia cannot see properly, they reply that they have already arranged an eye test and that the optometrist has said that there is nothing wrong.
The idea of visual problems occurring with dementia only makes sense when we remember that we DO NOT see with our eyes, we see with our BRAIN. Our eyes just allow the light in; it is our brain that interprets what we see. Most people with dementia will have problems interpreting what they see at some point in the disease and for many this happens early on. Occasionally it is even the first obvious sign of dementia.
Many of the problems we encounter when we try to get people with dementia to follow a certain route, to sit in a place indicated to them or to go in the direction we are pointing, occur because the person with dementia has trouble seeing. Visual problems may also explain why many people with dementia stop enjoying hobbies such as reading, sewing or model making. These problems with vision of course, play a huge part in loss of orientation.
How to tell if there is a problem
It is not easy to find out whether someone with dementia can see properly. Normal eye tests may not reveal a problem, not least because someone with dementia may not be able to answer the optometrist’s questions properly. Someone with dementia will generally lost the ability to explain what they do or do not see. Look out for vague ‘casting around’ when someone enters a new place and cautious movement sometimes accompanied by an attempt to ‘feel’ the way by holding on to furniture. Some types of dementia result in a kind of ‘fragmented’ vision so you may notice someone is unable to grasp successfully even when it is placed directly in the line of vision.
You can help by identifying yourself each time you meet (in case the person cannot recognise your face) by guiding someone rather than pointing the way and by saying casually the name of any object you are passing eg. “Here is your cup of tea.”
We know that people with dementia often lose the ability to distinguish between blue and black. This can cause extra problems at dusk or when the light is failing. People with Lewy body dementia have problems with patterns on floor and wall coverings so that they may see the patterns as differences in height and floor level. People with Lewy body dementia (and some other forms of dementia) may also see things which the rest of us cannot (so-called ‘hallucinations’).
It is probably best to assume that someone with dementia has some visual impairment or difficulty and be ready to help.
About the author
Mary works for a national dementia charity and is an Associate Director of ELM (End of Life Management Ltd). She has had considerable experience of caring for elderly relatives and friends and worked in the NHS for 9 years. Earlier publications include books on Caring and on GP Practice Management, in addition to articles in nursing and social care journals and magazines. Mary has published her new book this month by Hammersmith Books called ‘The Essential Carer’s Guide to Dementia’ and each month she will offer practical advice on how to deal with dementia.Last modified: June 10, 2021