Alzheimer’s and Eyesight

Our eyes and brain are intrinsically linked by the optic nerve. Images are passed from the eyes to the brain by sending neurons through this neve to be interpreted by the visual cortex. In patients with Alzheimer’s, the neurons can be interrupted and send faulty signals to the visual cortex, resulting in various problems.

It is important for both patients and caregivers to understand what impact Alzheimer’s can have on vision. Losing any element of one’s independence is extremely alarming for most patients, so learning more about what is happening and how to cope can help patients come to terms with their diagnosis and live healthy and full lives. For caregivers, it is important to know how best to help their patients and provide compassionate care for individuals of all ability levels.

There are a few ways that vision can be impacted by Alzheimer’s including:

1. Decreased depth perception
   The biggest issue that patients with Alzheimer’s report is difficulty with spatial reasoning including depth perception making it hard for the person to tell how far away or close something is. This may cause frustration as a patient may knock over something that looks to be far away or cannot reach something that appears to be closer.
   
   
2. Loss of peripheral vision
   Your peripheral vision allows you to view things that are all around you without turning your head. This is why you can view things “out of the corner of your eye” that may be sitting next to you or on a table in front of you. Some Alzheimer’s patients experience a narrowing of their visual field which limits what they can see significantly.
   
   Caregivers should be mindful not to inadvertently sneak up on patients and should place items directly in front of the person so that they can see them.
   
   
3. Trouble following moving objects
   When the information passed through the optic nerve is disrupted, objects in motion may appear momentarily still, as if you are slowly flipping through a picture book but pausing ever so slightly on each page. This phenomenon can make watching TV unpleasant and can cause slower reaction times in patients.
   
   
4. Trouble discerning between colors
   Individuals with brain diseases sometimes report problems differentiating between colors. If this is the case, try to incorporate items with higher contrast into the person’s environment.

This list is by no means all-inclusive, so if you or a loved one are experiencing new symptoms it is best to consult with a doctor to learn more. It’s important to note that these symptoms can not definitively confirm an Alzheimer’s diagnosis, but they can give early warning signs that someone may develop more significant symptoms down the line.

Doctors and scientists continue to do more research on the connection between our eyes and brain and may one day be able to diagnose brain diseases like Alzheimer’s using a simple vision test. For now, it is important to get routine eye exams and consult an ophthalmologist if you or someone you care for are experiencing unusual visual disturbances.