ABSTRACT Vision impairment (VI) is a significant public health problem among older adults. VI impacts a broad range of activities and is associated with reduced quality of life and poorer physical and mental health. As the population is aging, VI will become an increasingly important problem. Yet, data on VI in the oldest old (aged 80+) are limited. Available data suggest that a significant proportion of older adults have uncorrected refractive error (URE) – a condition that is easily addressed with spectacles – as well as vision-limiting cataract. While distance visual acuity is the most commonly measured aspect of VI, contrast sensitivity (CS; the ability to differentiate objects in low light settings) is also important for many activities. However, few population-based studies have measured contrast sensitivity in older adults; data are needed to understand the impact of distance acuity and contrast sensitivity deficits in the oldest old. In this study, we will add distance visual acuity and CS tests to an already funded, one-time visit in the homes of 4,200 older women who have participated in the Women’s Health Initiative (WHI) for nearly 30 years. These data will be used to characterize the prevalence of VI in the oldest old (Aim 1) and to assess the impact of VI on social, psychosocial, cognitive, and physical health indicators (Aim 2). Given the unique opportunity to link to an ongoing cohort, we will be able to describe cross-sectional associations (Aim 2a) and to prospectively evaluate trajectories of functional decline (Aim 2b). Additionally, we will utilize the WHI-Medicare claims link to analyze associations between VI and healthcare utilization and costs (Aim 2c). We will recommend eye care for individuals with VI and will characterize differences between those who seek care vs. those who do not and will examine reported barriers to care (Aim 3a). By engaging a patient care navigator, we aim to help facilitate care for those who do not initially seek it, and we will evaluate the potential impact of patient care navigation on improving uptake of needed eye care (Aim 3b). Adding these vision measures to the rich repository of WHI data provides a unique opportunity to evaluate the role of VI on a broad range of health domains. Project results will be used to develop interventions to improve vision health in older adults, with the ultimate goal of extending independence and improving quality of life in older adults. Renowned vision experts have highlighted the need for obtaining quality estimates of VI in the oldest old, in order for health systems to prepare for serving the growing population of affected individuals. This innovative project fills an important gap in our knowledge of VI and its impact on the lives of our society’s oldest members.