University of California Health researchers believe the initial signs of dementia could be detected by ophthalmologists if they diagnose a condition known as posterior cortical atrophy (PCA), which is also referred to as Benson syndrome.

This condition affects areas of the brain responsible for tasks such as spelling, arithmetic, spatial perception and complex visual processing, and is sometimes described as the visual variant of Alzheimer's disease.

Chaplow suggested that faster diagnosis of PCa could be beneficial for many patients who are in the initial stages of Alzheimer's disease development.

Signs of Benson syndrome, a key indicator for early diagnosis of dementia, usually appear before the age of 60, which is earlier than the first signs of memory loss and confusion in people with Alzheimer's disease.

Researchers believe the syndrome is underdiagnosed and want to raise awareness of it and its links to early diagnosis of dementia.