Blurry Pictures and Hidden Numbers Flag Lewy Body Dementia

Jeff's Daily Pick. A picture of a penguin that slowly comes into focus may help catch the dementia linked to Parkinson's early, before people notice anything wrong.

In Australia, researchers at the University of Queensland's Queensland Brain Institute and Mater Hospital Brisbane developed two visual tests to detect early dementia in Lewy body disease, which includes Parkinson's disease and dementia with Lewy bodies. The study, led by Emily McCann and neurologist Peter Nestor, was published in the Journal of Neurology and announced on October 13, 2026.

The two tests

Lewy body disease is the second most common degenerative dementia, caused by clumps of a protein called alpha synuclein inside nerve cells. Difficulty processing visual information is an early feature and can appear before other signs of dementia, Nestor said. The Graded Blurry Image test probes the ventral visual stream, which recognizes objects: people identify pictures, such as an emperor penguin, that start blurred beyond recognition and gradually sharpen. A second test, for simultanagnosia, probes the dorsal stream by asking people to find numbers hidden in a field of black dots.

The results

The team tested 53 people with Lewy body disease, including 27 with Parkinson's who had no recognized cognitive symptoms, and compared them with 29 people with Alzheimer's disease and 54 healthy adults. Visual impairments were more prominent in Lewy body disease than in Alzheimer's and were detectable even in some cognitively asymptomatic patients. Lewy body patients were impaired on both tests, whereas object recognition was relatively preserved in Alzheimer's. Visual processing scores were strongly associated with visual hallucinations. "Hallucinations have often been referred to as a risk factor for dementia, but our findings suggest they are a sign of the dementia itself," Nestor said.

Telling Lewy body dementia from Alzheimer's matters for treatment, because people with Lewy body disease can react badly to some antipsychotic drugs. A cheap, quick visual test that flags the problem early would help clinicians tailor care, and could track change in trials. The next step is testing the same tasks in larger groups followed over years.