In that ophthalmologic abnormalities have been described in patients with dementia, Kenneth M. Langa, from the University of Michigan Medical School (Michigan, USA), and colleagues assessed the extent to which poor vision and treatment for visual disorders affects cognitive decline.  Analyzing Medicare data (1992 through 2005) and linking it to the Health and Retirement Study, the team followed 625 elderly US study participants with normal cognition at the study’s start. They found that those subjects with very good or excellent vision at baseline had a 63% reduced risk of dementia over the 8.5-year follow-up period.  Further, study subjects with poorer vision who did not visit an ophthalmologist had a 9.5-fold increased risk of Alzheimer disease, as well as a 5-fold increased risk of cognitively impairment without dementia.  The team also found that fpoorer vision without a previous eye procedure increased the risk of Alzheimer disease 5-fold. For Americans aged 90 years or older, 77.9% who maintained normal cognition had received at least one previous eye procedure compared with 51.7% of those with Alzheimer disease. The researchers conclude that: “Untreated poor vision is associated with cognitive decline, particularly Alzheimer disease.”