Linking Vision Impairment & Cognition

Blindness and visual impairment affect 1 in 11 Americans age 65 and older. With the aging of the U.S. population, the number of older adults impacted by visual disability is expected to continue to increase rapidly over the next 30 years.

Joshua Ehrlich, M.D., M.P.H., Assistant Professor of Ophthalmology and Visual Sciences, along with colleagues at the Kellogg Eye Center and the Institute for Social Research, is working to understand the impact of visual impairment on the physical and cognitive health of an aging population. “We’ve found that as vision gets worse, so too does cognitive health,” he says.

Drawing on population health and survey research, Dr. Ehrlich’s research seeks to optimize the health of older individuals and populations with visual impairment, both in the U.S. and globally. Some of his most exciting recent work draws upon various epidemiologic studies, including the National Health and Aging Trends Study (NHATS) and the Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD).

The NHATS—a U.S.-based study of more than 8,000 adults 65 and older—examines health and disability in individuals as they age. “We are implementing a new battery of vision tests in NHATS that will open the door to novel research to understand the role of vision on late-life health and disability,” says Dr. Ehrlich.

Dr. Ehrlich’s interest in better understanding the relationships among vision, cognition and aging led to his work with LASI-DAD. “In this study of 4,000 adults 60 and older across 18 states and territories in India, we’re trying to understand risk factors for dementia, including the impact of visual impairment on brain health and whether the eye is a biomarker of future cognitive changes,” says Dr. Ehrlich. “We’ve found that lower levels of vision are related to poorer cognitive performance across all domains of cognition.” In addition, the study aims to estimate the prevalence of dementia and cognitive impairment.

With the goal of fostering collaboration and catalyzing scientific advances, Dr. Ehrlich and other researchers have recently established the SENSE Network (sensenetwork.org), an international network of sensory aging researchers. This global collaboration is working to accelerate research examining the role of sensory function—including vision—on health and aging.