Cognitive decline and vision loss are 2 major problems of older age. Both will increase significantly in line with population growth and longevity. The number of people with dementia will triple, rising from 50 million to 132 million in 2050. Similarly, it is projected that the number who have blindness will rise from 38 million to 115 million in 2050. Blindness and dementia have a substantial adverse effect on quality of life and social and economic activity, burden national and commercial health care budgets, and diminish daily experience for those affected. However, the parallels between the 2 conditions extend beyond descriptive epidemiology. The well-worn assertion that the eye is not just the only visible part of the central nervous system but also the window to the soul remains pertinent. Hinton et al1 described changes in the optic nerve and retina that were associated with Alzheimer disease. Therefore, it is logical to seek and quantify associations between cognitive and visual function.