A new study has found that struggling to read more than six lines on an eye chart with fading letters may serve as a visual ‘yellow light’ for older adults that routine exams may fail to detect.
While eye health professionals have long known that contrast sensitivity can detect certain vision problems, “we didn’t have a threshold or number that told us where on this contrast sensitivity chart patients start to experience problems with their vision,” said neuro-ophthalmologist Associate Professor Lindsey De Lott from the University of Michigan.
“Traditional eye charts can miss important vision changes that often occur as we age because they use high contrast with black letters on a white background,” Assoc Prof De Lott said.1
“But we can also measure vision using letters in different shades of grey. In these lower-contrast charts, such as the one used in our study [a Pelli-Robson chart], the letters become progressively lighter and harder to see.”
A University of Michigan study, published in JAMA Ophthalmology,2 used data from 4,475 older adults in the United States and identified a threshold of 1.60 logCS as the point at which contrast sensitivity was associated with self-reported visual disability. Each 0.1-unit decrease in baseline CS was associated with 12% higher odds of developing incident visual disability.
… having the threshold “makes the test more actionable for clinicians and more meaningful for patients
Self-reported visual disability was defined by difficulty recognising faces, reading newspaper print, or seeing the television across a room.
Study co-author Shu Xu, a postdoctoral fellow at the University, said having the threshold “makes the test more actionable for clinicians and more meaningful for patients.”1
“It also provides researchers in public health, aging and the social sciences with a concrete marker for studying how vision affects older adults’ independence, wellbeing and health outcomes.”2
References
- University of Michigan, Faded letters, early warnings: A new clue for aging eyes (news), available at: news.umich.edu/faded-letters-early-warnings-a-new-clue-for-aging-eyes [accessed July 2026].
- Xu S, Nguyen M, De Lott LB, et al. A clinically relevant threshold of impaired contrast sensitivity among older US adults. JAMA Ophthalmol. 2026 May 28:e261570. doi: 10.1001/jamaophthalmol.2026.1570.
