Nonrefractive visual impairment, not due to needing glasses, has increased significantly among Americans in recent years, and the higher incidence of diabetes may be responsible.

The finding came from new research, conducted by a team at the Johns Hopkins University School of Medicine, Baltimore, and was published in JAMA, December 12 issue.

Background information in the report stated: “It is estimated that more than 14 million individuals in the United States aged 12 years and older are visually impaired (