Washington, Oct 14 (IANS) Weakening of vision seems to be more common among diabetics than in people with normal health, according to a study.Approximately 14.6 million Americans had diagnosed diabetes mellitus in 2005 and another 6.2 million had undiagnosed diabetes, according to the study.

The number of individuals with diagnosed diabetes is estimated to increase to 48.3 million by 2050. “Diabetic retinopathy (damage to the retina caused by diabetes), one of the most common complications of diabetes, is considered to be one of the major causes of blindness and low vision,” the authors wrote.

Although studies suggest that controlling glucose and blood pressure has reduced the rate of retinal diseases, other ocular (relating to eyes) conditions suffered by diabetics like cataract and glaucoma may increase the risk of visual impairment. Additionally, decreased vision caused by an abnormal shape of the cornea is also common among people with diabetes.

Xinzhi Zhang and colleagues at the Centres for Disease Control and Prevention, Atlanta, used data from the National Health and Nutrition Examination Surveys from 1999 to 2004, which included 1,237 adults with diabetes (average age 59) and 11,767 adults without the disease (average age 45) and also measured their visual acuity before and after optical correction.

Participants’ vision was tested while they were wearing any glasses or contacts they typically used, and their demographic information was also noted, according to a release of American Medical Association.

An estimated 11 percent of American adults with diabetes had some form of visual impairment (3.8 percent uncorrectable and 7.2 percent correctable), while only 5.9 percent of those without diabetes had some form of visual impairment (1.4 percent uncorrectable and 4.5 percent correctable).

The report appeared in the October issue of Archives of Ophthalmology.