In this blog I'll discuss all the reasons someone should have glasses and the occasions when someone may be better without them.
One of the most common phrases I hear from relatives is, "my mum has dementia and she doesn't read so she won't need any reading glasses". There are two situations here. The patient isn't reading because they can't comprehend it due to their dementia or they aren't reading because they haven't got any glasses to read with and it's been assumed that's it's due to dementia. Either way, "reading glasses" is really just a term for glasses that help with ANY near task. Looking at family photos, reading birthday cards, card games, board games, and seeing their food to name a few. It can be difficult to get elderly people to eat enough food at the best of times. Maybe allowing them to see what their eating by wearing a pair of glasses may just help a little. Even if it doesn't, wouldn't you like to be able to see what you are eating or what someone is feeding you if you're not able to do it yourself?
It's a similar situation for distance glasses or "driving/tv glasses". Some opticians will name them after the tasks which most people use them for but in actual fact they are just glasses to help the person see everything in general life that is past about a meter. Seeing the faces of family members, the carers, doctors, nurses, anyone who comes to see them.
Often people with dementia can lash out of or become aggressive. One of these reasons could be that they don't recognise who is approaching them because they are blurry. So even if the patient doesn't drive or isn't interested in the television, it doesn't mean they should be living their whole life in a blur. If patients are able to walk and could be at risk of falls, this is another reason to correct their vision with glasses.
I had a patient once who was very short-sighted and her daughter was worried that she was forgetting who she was as she never recognised her when she came to visit. The actual reason was because she couldn't see past 10cm clearly. Her daughter walking in was just a blob of colours. Once she got her new glasses, it was no longer a problem and she wore them all the time.
When are glasses inappropriate?
There are a few situations when glasses won't help or may even be a danger to patient.
1. The patient had dense cataracts or end stage glaucoma or end stage macular degeneration (or any other eye condition that renders the patient unable to see). In these cases glasses will be of no benefit. However, in patients with dementia sometimes they think they can see ok and maybe they've worn glasses all their life. If a patient becomes distressed when their glasses are removed then let them keep them on, even if they aren't benefiting their sight. If their glasses break and they want to replace them, the easiest thing to do it to buy some cheap ready readers as they are just for the feeling of having glasses rather than the sight.
2. The patient doesn't need glasses for distance and doesn't settle down very often, i.e they constantly walk around and often get up even if someone asks them to sit down. In this case I wouldn't prescribe reading glasses in case the patient gets up and starts wandering when wearing them and is then risking falling due to their distance vision being blurred through the reading glasses. I would only prescribe reading glasses if there is someone who can stay with the person while eating or looking at photos and immediately take them off of they start to get up and wander off. The glasses shouldn't be left anywhere where the patient can help themselves and put them on.
3. The patient has one eye that is clear for distance and one that is clear for close. This is done artificially in some cataract patients. One cataract is removed and the eye is corrected for distance vision then when the second cataract is done, it is left clear for close to. Some people have this naturally in which case they have no need for glasses.
4. The patient constantly have their eyes closed.
5. Wearing glasses distresses the patient and they will just throw them off. In this case we should still reassess each year as their a attitude towards glasses will likely change as their dementia changes.
6. Very advanced dementia where a patient has no visual demands at all (not even looking at people who come in so showing any interest or response to photos etc)
Bifocals or varifocals?
I prescribe bifocals or varifocals for the majority of dementia patients who are none mobile. Having a bifocal means they have one pair of glasses which can be kept on to see general vision as well as close up without having to swap between taking glasses on and off or between 2 different pairs. Often the patient won't be cognitively able to take them on and off and put on a correct pair of glasses for a specific task, and also may not realise if they are sat watching tv in their reading glasses. Bifocal or varifocal glasses for patients who are none mobile won't increase risk of falls. I would only prescribe them for patients who walk if they are very stable or have always worn this type of glasses and haven't been falling in them.
A situation when mutifocal glasses are inappropriate is when a patient is bedbound and spends the majority of time lying flat in bed. If their tv is high up on the wall this might be ok. If it is level with the bed then the patient may be watching it at an angle where mutifocal glasses won't be appropriate. If the reading area is in the way then a single vision distance pair is more appropriate for watching tv and separate close glasses for near tasks. This doesn't mean they can't have a bifocal for when they are sat up on bed if they want one.
Dementia eye test
Levels of dementia vary greatly between patients even if they have the same type of dementia. Some can read the chart and carry out a normal eye test whereas some can't tell me what the can or can't see. We have specialist training and equipment that allows us to measure a patient prescription for glasses and that allows us to see the back of the eye to detect any eye problem that may reduce sight. This allows us to know whether glasses would actually benefit the wearer or whether their eyes are too damaged to benefit from glasses correction. I'll do a separate blog post all about the dementia eye test so keep an eye out if you'd like more information.