Impact of Alzheimer's on vision

05 March 2026

Alzheimer’s disease is a progressive neurodegenerative disorder that primarily affects memory and other cognitive functions. However, there is increasing evidence that it also significantly impacts the visual system. These changes are not always due to primary eye diseases, but rather to alterations in the areas of the brain responsible for visual processing.

Why does Alzheimer’s affect vision?

Alzheimer’s disease is characterized by the accumulation of beta-amyloid plaques and neurofibrillary tangles of tau protein in the brain. Although it initially affects structures related to memory, such as the hippocampus, as the disease progresses it also involves the occipital and parietal regions, which are essential for interpreting visual information.

In addition, recent research has identified structural changes in the retina, such as thinning of the retinal nerve fiber layer and alterations in ganglion cells. These findings have sparked interest in the retina as a potential early biomarker of the disease.

Most common visual alterations

Visual disturbances in Alzheimer’s are usually related to how the brain processes images rather than to visual acuity itself. The most common findings include:

• Reduced contrast sensitivity

• Difficulty distinguishing colors

• Problems with depth perception and spatial orientation

• Alterations in eye movements

• Difficulty reading or following lines of text

• Problems recognizing objects or faces in more advanced stages

In some cases, particularly in a variant known as posterior cortical atrophy, visual symptoms may be the first clinical sign, even before noticeable memory impairment appears.

Importance of early diagnosis

Identifying visual changes can provide valuable information for the early detection of Alzheimer’s disease. Evaluations that include visual processing tests, visual field studies, and retinal imaging can complement neurological assessments.

Recognizing these alterations also helps in adapting the patient’s environment, improving lighting, contrast, and signage. These adjustments can reduce the risk of falls and help improve the patient’s overall quality of life.