Alzheimer’s disease changes how people see their surroundings because it affects not just the eyes but also the brain areas responsible for processing visual information. The brain’s occipital lobe, which interprets what the eyes see, can be damaged by Alzheimer’s. This means a person might look at an object and see it clearly but struggle to understand what it is or where it is in space.
One common problem is difficulty with depth perception. People with Alzheimer’s may misjudge distances, which can make walking or moving around tricky and increase the risk of falls. This isn’t because their eyes are failing but because the brain can’t properly process spatial relationships.
Another issue is motion blindness, where a person has trouble seeing things that are moving. For example, they might not notice a car driving by or someone walking toward them. This happens because Alzheimer’s can damage the part of the brain that processes motion, called the V5 or MT area.
Color and contrast sensitivity also decline. This means it becomes harder to tell apart colors that look similar or to see objects that don’t stand out well from their background, like a white plate on a white tablecloth. Everyday tasks like choosing clothes or reading can become confusing.
Additionally, Alzheimer’s can cause changes in the retina, the part of the eye that sends visual signals to the brain. These changes can happen early in the disease and contribute to vision problems. The combination of retinal damage and brain processing issues leads to the visual difficulties people with Alzheimer’s experience.
In short, Alzheimer’s changes vision by damaging the brain’s ability to interpret what the eyes see, affecting object recognition, motion detection, depth perception, and color discrimination. This makes the world look different and more confusing for those living with the disease.
