Triangle test detects Alzheimer’s signs 12 years early

A new study has found that a simple vision test can detect early signs of Alzheimer’s disease up to 12 years before a formal diagnosis. The research involved over 8,000 healthy adults, of whom 537 later developed dementia. These participants performed poorly on a test where they pressed a button when a triangle appeared among moving dots. The study, published in the journal Neurology, suggests that visual sensitivity may be affected by Alzheimer’s even before memory loss occurs. The researchers believe that Alzheimer’s impacts the parts of the brain responsible for vision first, while memory areas become damaged later. Other visual problems linked to dementia include difficulty distinguishing colors and controlling eye movements. People with Alzheimer’s often struggle to filter out distractions, affecting their eye coordination. They may also fail to recognize new faces properly, not because of memory issues, but due to ineffective eye movements. Previous research indicates that good eye movement can enhance memory. The study authors noted that people who engage with reading or watching TV tend to have lower dementia risks—likely due to increased cognitive engagement. Additionally, being bilingual may help delay dementia onset, suggesting that mental activity plays a crucial role in brain health.