Alzheimer’s disease affects the brain, but the first signs may show up in the eyes. Scientists now believe early changes in vision could point to early Alzheimer’s—even before memory loss begins. If you’re concerned about brain health, paying attention to subtle vision problems may help detect cognitive decline sooner.
Let’s look at how this happens, what you can watch for, and why regular eye care plays a role in protecting your long-term health.
The Link Between Vision and Alzheimer’s
Alzheimer’s disease causes damage in the brain. We know that. But the retina, which connects directly to the brain, can reflect changes linked to earlier stages of cognitive decline. Research shows that retinal changes may offer clues to what’s happening neurologically. For example, people with early Alzheimer’s often show reduced blood flow in the retina, which some eye exams can detect.
Recent findings support this connection. A 2025 study from The Jackson Laboratory published in Alzheimer’s & Dementia found that mice with a genetic mutation known to raise Alzheimer’s risk also had abnormal changes in the small blood vessels of the retina. The same research team, based at The Jackson Laboratory, previously linked similar changes in the brain to early dementia risk and found signs of damage in specific retinal cells. Taken together, the evidence strengthens the idea that the retina may be a useful early marker for Alzheimer’s disease and related dementias.
Also, the visual processing center of the brain may be affected early on. This can lead to vision problems before memory loss begins. Because of this, the eyes offer a valuable window into changes linked to cognitive decline.
Early Vision Problems to Know
Patients in the early stages of Alzheimer’s disease may not notice vision loss at first. But over time, common vision problems may include:
- Trouble judging depth: People may have difficulty knowing how far away objects are.
- Difficulty with contrast: It may become harder to see steps, curbs, or low-contrast items.
- Peripheral vision changes: Some people report “tunnel vision” or missing things off to the side.
- Difficulty reading: Tracking words may take effort or feel confusing.
- Visual misperceptions: Patterns or shadows can be mistaken for objects or people.
Patients in the early stages of Alzheimer’s disease may not notice vision loss at first. But over time, common vision problems may include trouble judging depth, difficulty with contrast, reductions in peripheral vision, and challenges when reading. Some people also experience visual misperceptions, where common objects or shadows are mistaken for something else entirely.
These changes are not caused by damage to the eyes alone. They often reflect how the brain processes visual information. In fact, a 2024 study from the University of California, San Francisco found that unusual visual symptoms—such as misidentifying objects or seeing things that aren’t there—can appear years before memory loss and may be early signs of a rare form of Alzheimer’s disease known as posterior cortical atrophy.
If you’re an older adult experiencing these changes, especially if you also have risk factors for cognitive decline, it may be time to talk with your doctor.
How Early Alzheimer’s Affects the Retina
The retina is a light-sensitive layer at the back of your eye. It acts like a camera, passing images to your brain through the optic nerve. In early Alzheimer’s disease, retinal changes may include:
- Thinning of the retinal layers
- Changes in blood flow in small vessels
- Build-up of amyloid plaques, a hallmark of Alzheimer’s, similar to those seen in the brain
Some eye exams now allow doctors to detect these features. Optical coherence tomography angiography (OCTA), for example, uses light waves to take cross-sectional images of the retina. It can show reduced blood flow or thinning in certain layers—both possible signs of early Alzheimer’s.
These tests are not yet used to diagnose Alzheimer’s. But in combination with neurologic assessments, they may soon play a role in identifying brain changes earlier.
Related Article: The Surprising Link Between Vision and Mental Health
Understanding Risk Factors
Age is the strongest risk factor for Alzheimer’s disease. Most cases appear after age 65. But family history, genetics, and lifestyle also play roles. Other risk factors include:
- High blood pressure
- Diabetes
- Smoking
- Lack of physical activity
- Poor diet
Because the eyes and brain share blood vessels and nerves, changes in one may reflect changes in the other. That’s why eye care can be an important part of overall health in older adults. Watching for early vision problems can help signal possible changes in cognitive function.
Why Eye Care Matters
Regular visits to the eye doctor do more than update your glasses. They allow experts to take a close look at your optic nerve and retina—areas that can reveal much about your overall health. For older adults, these exams may also help identify early signs of cognitive decline.
Eye care supports brain health in several ways. A comprehensive exam can detect early vision loss that might point to neurological problems. It also helps monitor the health of the retina, including signs of reduced blood flow or structural changes. These exams can rule out other eye conditions, such as glaucoma or age-related macular degeneration, which may have similar symptoms. If something unusual is found, your doctor can recommend further evaluation to explore the possibility of early Alzheimer’s disease.
Not every finding leads to a diagnosis. But catching these signs early can open the door to additional testing, supportive care, and lifestyle changes that may help slow the progression of cognitive decline.
What You Can Do
If you notice new vision problems—especially if you’re also concerned about memory—don’t ignore them. Keep track of what you’re experiencing and share the details with your eye doctor. This might include trouble reading or recognizing faces, feeling disoriented in familiar places, missing objects in your side vision, or misinterpreting visual cues while walking or driving.
It’s important to speak openly about your concerns. While many vision changes are linked to aging or common eye conditions, symptoms that don’t follow the typical patterns may signal something more. A careful eye exam can help determine if further testing is needed.
Remember, regular eye exams aren’t only about preserving your sight—they also give insight into your brain health.
If you’ve noticed changes in your vision or are concerned about how they may relate to memory or brain health, schedule an appointment with amaEyes to get a clear picture of your eye and cognitive wellness.