More than 1.5 million Americans age 80 and older have low vision– 16.7% of the 80 and older population.
Congdon NG, O'Colmain BJ, Klaver CC, et al. Causes and Prevalence of Visual Impairment Among Adults in the United States. Archives of Ophthalmology. 2004; 122(4): 477-85. http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=AbstractPlus&list_uids=15078664