by Fernanda Pires And Originally published in Michigan News
Struggling to read more than six lines on an eye chart with faint letters can serve as a visual “yellow light” for older adults — raising red flags that routine tests sometimes fail to detect.
A new study from the University of Michigan, has been published Jama Ophthalmologyshows that this threshold on the Pelly-Robson chart can indicate everyday vision problems that standard eye exams might miss.
“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,” says the neuro-ophthalmologist. Lindsey D. Lott.
“But we can also measure vision using letters in different shades of gray. On these low-contrast charts, like the one used in our study, the letters get progressively lighter and harder to see. We call this contrast sensitivity.”
According to de Lott, researchers have long known that contrast sensitivity is a good way to identify specific vision problems.
“But we didn’t have a threshold or a number that told us when patients on this contrast sensitivity chart started experiencing problems with their vision in their daily lives, such as trouble recognizing faces, reading print or watching television,” he said.
According to the researchers, prior to this study, yellow light was only defined based on patients reporting any visual problems. Now, doctors may be able to help them before they reach the red light.
“This makes testing more efficient for clinicians and more meaningful for patients,” said Shu JuPostdoctoral Fellow at the U-M Institute for Social Research.
“It provides public health, aging and social science researchers with a concrete marker to determine how vision affects independence, well-being and health outcomes in older adults.”
Many older adults with normal visual acuity scores still had poor contrast sensitivity and reported vision problems, highlighting a gap in routine care.
Traditional vision tests can miss important aspects of visual function that affect daily life.
A difficult diagnosis problem
Many older adults report that their vision is not as reliable as it used to be.
Some struggle to navigate uneven sidewalks at dusk, others have difficulty reading medication labels in dim light or seeing objects that are not clearly visible against their background.
Contrast sensitivity is the ability to detect subtle differences between a target and its background.
Poor contrast sensitivity has been linked to important real-world outcomes, including falls, difficulty driving, and loss of independence.
“Clinicians and researchers often label two standard deviations below the mean as disability, which simply tells you that you’re worse than average — not that you’re likely to have problems in real life,” Xu says.
“Our work provides that missing link by connecting test results to the real-world everyday experiences of older adults.”
According to the researchers, this is the first study to directly link contrast sensitivity to self-reported visual problems in everyday life in older adults.
They used data from 4,475 Medicare beneficiaries in the National Health and Aging Trends Study, making the findings nationally representative.
Previous studies often relied on small clinic samples or statistical cutoffs that were not tied to people’s everyday experiences.
“Our functional anchoring makes thresholds more relevant for clinical decision-making and public health,” de Lott said.
“We found that people began to report problems even when measured using traditional charts they would not be considered visually impaired. This means that real-world problems may emerge earlier than previously recognized.”
What does search for care mean?
Adults age 65 and older who report poor vision despite normal test results may benefit from a contrast sensitivity test.
Early changes in vision may occur before normal visual acuity is lost, and a variety of causes can be treated.
“We are currently building on this work by examining whether older adults with contrast sensitivity below the newly identified threshold are at greater risk of future decline in health and independence,” Xu said.
“By following people over time, we hope to better understand how this functionally meaningful threshold can identify older adults at risk of functional decline and support healthy aging.”
Study: “A clinically relevant threshold for impaired contrast sensitivity in older US adults” DOI: 10.1001/jamaophthalmol.2026.1570
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Previously published Also at michiganmedicine.org Creative Commons License
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