Dementia often occurs alongside eyesight problems, possibly because dementia and vision changes are more common as you age. This can cause additional confusion and upset for the person with dementia.
Dementia may also affect parts of the brain that process visual information, making it difficult to see and process what you’re seeing. As a result, a person with dementia could have normal vision acuity (sharpness and clarity of vision) but still have difficulty seeing clearly.
It’s also possible that dementia comes with eyesight challenges caused by degeneration and damage in some areas of the brain.
Getting eyes checked regularly and correcting any additional vision problems can help maintain a high quality of life, especially for those with dementia.
Dementia and challenged eyesight
Dementia develops from the degeneration of neurons (brain cells) or changes in how neurons function, resulting in cognitive loss. Dementia does not affect the eyes themselves, but it can affect how the brain processes visual information or adjusts the vision field.
Neural degeneration can affect the parts of your brain that process eyesight. Although it’s possible to have dementia and normal vision, damage to the neurons may eventually make it more difficult to see or interpret what the eyes see.
For example, depending on what part of the brain is affected, someone may start having problems calculating distance or recognizing familiar objects or faces. They could also have problems seeing what’s next to or under them when looking straight ahead (peripheral vision).
Dementia and vision problems may also co-occur because both conditions are common among older adults. Age-related vision loss can develop from conditions like macular degeneration and cataracts.
Some vision-related challenges in dementia may include:
- blurred vision
- loss of depth perception
- limited peripheral vision
- problems adapting to light and brightness changes
A 2023 research review found that visual impairment is actually associated with an increased chance of dementia. In fact, people with visual impairments had a 60% higher chance of developing dementia or other cognitive impairment.
However, the nature of the causal relationship between cognitive loss and vision loss isn’t completely clear. More research is needed to determine whether vision loss could cause cognitive loss or vice versa, or if both are affected by other factors.
Read about safety changes to your home for people with low vision.
What do dementia eyes look like?
It’s common for people with dementia to stare blankly at a wall or into the void as if distracted. They may also seem to avoid eye contact. This is often referred to as “glassy eyes” or “glazed eyes,” though it may have other causes.
In dementia, vision impairment may include a range of eyesight challenges that could affect the appearance of the eyes. A person’s vision sharpness and eye appearance will depend on their specific eye condition if they have one. For example, cataracts may cause the eyes to look cloudy.
Not all people with dementia will have the same vision problems.
Read more about the symptoms of dementia.
Although more research is needed on the link between dementia and visual impairment, some studies have identified specific eye conditions that seem to be more common among people with dementia.
A
However, researchers could not determine whether this was a causal relationship or whether a third common factor was at play.
Q: How can a caregiver help?A: “Scheduling a yearly check-up with an eye doctor to evaluate for vision problems and receive a prescription for glasses, if needed, is important. Other doctor appointments for the regular management of cholesterol, blood sugar, and blood pressure to support the health of eyes and brain may also help.”
— Shilpa Amin, MD, CAQ, FAAFP
Quotes represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Vision changes may be mistaken for hallucinations in some people with dementia. Hallucinations are visions or perceptions of something that other people in the same situation cannot see or perceive.
For example, a person with dementia and compromised depth perception might try to hold onto something that’s farther away than they think. This could appear as if they’re grabbing at air, but they’re actually underestimating their distance from the object.
Similarly, someone with dementia may have a hard time recognizing a familiar person. This could be because of loss of vision acuity or cognitive loss that prevents them from accurately interpreting what they’re seeing.
That said, it’s possible for someone with dementia to have hallucinations. They may see, hear, smell, feel, or taste something that’s not actually there. This is also associated with cognitive loss and neurological damage in some areas of the brain.
Read more about the complications of dementia.
Dementia doesn’t affect the eyes directly. Instead, it’s possible that what eyes see cannot be interpreted by the brain due to cognitive loss and neurological damage.
It’s also possible for someone with dementia to feel confused or lost, which could lead to glassy eyes.
Research has also found a link between some eye conditions and an increased risk of dementia, but it isn’t clear that one causes the other.
Getting eye exams regularly may help prevent some vision-related challenges in dementia. Other challenges may be managed with dementia treatment, although they may not be able to be reversed or stopped altogether.
