Your eyes can reveal symptoms of dementia long before memory starts to fade, says ophthalmologist

Healthy eyes: Modern imaging tools like optical coherence tomography (OCT) allow specialists to detect even minute changes that may hint at cognitive decline (Image: Pexels)

For centuries, poets have called the eyes the windows to the soul. Now, doctors are finding they might be windows to the brain as well. Researchers believe that the tiny, delicate structures within the retina can reveal much about how the brain is functioning, and even predict diseases like dementia before they take hold.

The eye gives us a unique, non-invasive glimpse into the nervous system, Dr Madhavi Jeste, Senior Consultant Ophthalmologist,  SL Raheja Hospital, Mahim, tells Moneycontrol. The retina, a wafer-thin sheet of nerve tissue lining the back of the eye, is directly linked to the brain through the optic nerve. “Because of this intimate connection, any changes in the brain — especially those caused by dementia — may leave visible traces in the retina. Dementia affects memory, thinking, and social abilities, interfering with a person’s daily life. As the disease progresses, we often notice similar degeneration in the retina,” she adds.

The most common form, Alzheimer’s disease, is rising sharply as people live longer, making early detection crucial to slowing its course.

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Dr Jeste describes the retina as "the window into the body", where doctors can literally see nerves and blood vessels in action. “Modern imaging tools like optical coherence tomography (OCT) allow specialists to detect even minute changes that may hint at cognitive decline” Dr Jeste explains:

Thinning blood vessels: When the retina’s blood vessels narrow and blood flow decreases, it can indicate a similar reduction in blood supply to the brain.

Thinning nerve fibres: Loss of retinal nerve fibres often corresponds to poorer cognitive performance. These delicate nerves mirror those in the brain, and their degeneration can signal early dementia.

Amyloid protein build-up: Tiny deposits of amyloid protein in the retina resemble the same abnormal proteins found in the brains of Alzheimer’s patients—one of the hallmark signs of the disease. “These findings suggest that the retina might be the brain’s mirror. By observing it, we can identify early warning signs, sometimes even before cognitive symptoms appear,” says Dr Jeste.

As dementia advances, the loss of nerve cells in both brain and retina may blur not only memory but also vision. “Patients might struggle with face recognition, distance judgement, or colour perception. Doctors examining the retina under light can often detect these physical and functional shifts, offering vital clues to the disease’s progression,” she says.

While retinal scans can’t replace brain imaging, they may soon become a valuable screening tool for at-risk individuals. “It’s not about replacing MRI scans. but about giving doctors an early, accessible way to assess brain health,” clarifies Dr Jeste.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.