Your loved one just had an eye exam, and their vision is fine. Maybe they even got a new prescription that works. But they still seem to be having trouble seeing the world around them, and it’s getting worse, not better.
It’s easy to assume that’s just part of getting older. But vision changes in dementia go beyond the eyes.
Why the Eye Exam Says Everything Is Fine
In dementia, vision is greatly affected by the brain’s ability to process and understand what’s being seen.
That’s why changing their glasses or their prescription often doesn’t seem to help. It’s not actually the vision. It’s neurological. It’s the brain that’s changing how they perceive the world.
The eyes could be fine, but the brain’s image processing centers are not.
Here are the common changes I see in dementia, a few less common ones, how each differs from normal aging, and what you can do to make life safer and less confusing for your loved one.
Common Vision Changes in Dementia
Tunnel Vision (a Decreased Visual Field)
The first common change is a decreased visual field, sometimes called tunnel vision. The person with dementia can only see what is directly in front of them, and it’s much easier for them to totally miss what’s off to the side.
You might notice it at a meal. They miss food on the side of the plate, or miss the side plate altogether. You might see them bumping into objects when they walk, because they don’t see what’s in their peripheral vision.
The visual field we experience starts to narrow into a tunnel, and for many people with dementia it shrinks dramatically.
So the next time your loved one asks, “Who keeps moving my stuff?” or seems startled when you come into their field of view, it could be a sign their visual field has shrunk.
Depth Perception Problems
Another common change has to do with depth perception. The person with dementia starts having trouble judging how close or far away things are.
You might notice they:
- Are more hesitant around stairs
- Reach for a cup and miss it
- Misjudge a step
- Think the floor is uneven when it isn’t
This happens because the brain’s spatial processing areas are affected. Something as simple as pouring a cup of coffee can turn into a big mess when they miss the cup.
Depth perception may decrease slightly for all of us with normal aging. In dementia, it’s much more significant.
Trouble With Color and Contrast
Vision also changes through color and contrast sensitivity. A white plate on a white tablecloth can seem to just disappear. A dark rug on the floor might look like a hole.
Some color loss is normal with aging, especially with blues and greens. That’s okay. But in dementia, the brain’s visual pathways are disrupted. So even with perfect eye health or a perfect prescription, colors seem to blend together.
At lunchtime they may be wondering, “Where’s my sandwich?” because it blends right into the white plate. That’s why you may have heard the advice to use a brightly colored plate for someone with dementia.
The bathroom can be an issue too, if they can’t find the toilet seat. A brightly colored toilet seat cover can help there. I go through the other reasons the bathroom gets hard in why people with dementia struggle in the bathroom.
Visual Agnosia: Not Recognizing Objects or Faces
Visual agnosia is something commonly tested for in a full neuropsychological evaluation. It means trouble recognizing objects and faces.
It’s not about their eyesight. It’s about their brain being able to understand what they’re seeing. A person might not recognize their own reflection in the mirror. They might use their pen as a toothbrush.
With normal aging, we might have trouble finding the name for something. It’s on the tip of our tongue, but we eventually come up with it. In dementia, the link between what they see and their memory is disrupted, and the brain doesn’t fully understand what it’s looking at.
What can help here is to call out the item as you hand it over. “Here’s your pen.” And keep their surroundings as uncluttered and predictable as possible.
Less Common Vision Changes in Dementia
Then there are a few changes that are less common.
Visual Hallucinations
I’ve talked about visual hallucinations a lot on the channel. The person sees something that isn’t actually there, but their brain is showing them that it is.
With normal aging, we can have visual illusions, which means misinterpreting what we see. You walk into a dark room, see a clump on the bed and think it’s your dog. As you get closer, you realize it’s just the comforter bunched up.
In dementia, the brain often produces things that aren’t there at all. They might walk into a bedroom where the bed is perfectly made and nothing is on it, and see a dog on the bed. Their brain is actually seeing the dog.
That’s why I never recommend arguing with or correcting someone with dementia who is having visual hallucinations. When you say “it’s not there,” that isn’t true for them. It is there in their brain. They are seeing it.
I go deeper into what causes them and how to respond in dementia and hallucinations.
Motion Blindness
Something even less common is motion blindness. Some people with dementia lose the ability to detect motion. Cars might look like they’re at a standstill even though they’re moving, which makes crossing the road dangerous, not to mention driving.
With normal aging, our ability to detect motion might decline slightly, but we can still tell something is moving. In motion blindness in dementia, that’s gone entirely. They can’t tell that it’s moving.
Simultanagnosia: Seeing One Thing at a Time
Another less common change has a complicated name, simultanagnosia. It means the person can only focus on one part of a visual scene at a time.
They might see the plate, but not the utensils. They might see one person in a group, but not the rest of the people.
With normal aging, visual scanning might slow down, so it takes longer to take in everything around us. But the brain is still able to take it all in. In dementia, the person is literally only able to take in one part of the scene at a time.
What You Can Do to Help a Loved One With Vision Changes
That’s a lot of information. So here’s what you can do if you suspect your loved one with dementia is having visual changes.
- Use high-contrast colors wherever you can: dishes, toilet seat covers, colored tape on door frames. Anything that sets apart what you want them to focus on.
- Simplify the environment. Removing clutter can help them focus their attention.
- Label what they use most. Simple, clear, easy-to-read labels on the drawers they open most often.
- Improve the lighting. Bright, even lighting reduces shadows, which can be misinterpreted as people, animals or holes. Night lights in hallways can help too.
There are so many things we can do to make the environment easier for our loved ones to navigate.
Figuring out which of these fits your loved one, and your home, is exactly what we talk about inside the Care Collective with members who are going through it right now. You get the information, and you get connection with other caregivers to share ideas, support, tears and laughs. You can learn more here.
