You probably do not think very often about what it means to live as an independent adult, but it requires you to be able to shop for groceries, prepare meals, do laundry, and perform light housework — so-called instrumental activities of daily living (IADL).

Unsurprisingly, a recent study found the probability of an elderly person losing their ability to perform IADL was reduced by up to 10 percent with each additional annual eye examination visit. Now, a new study led by researchers at Purdue University reinforces these earlier findings. The new study suggests loss of visual acuity negatively impacts an elderly person’s IADL levels, which in turn increases their risk for mortality. “Prevention of disabling ocular conditions, treatment of correctable visual impairment, and interventions designed to prevent the effect of visual impairment on IADL declines may all reduce mortality risk in aging adults,” wrote the authors in their study.

Loss of Sight

For many people, loss of eye sight would be the single worst disability. Not only would many IADL activities become difficult if not impossible, but walks in the park and long afternoons spent reading a good book would be lost as well. Visual acuity (VA), it seems, is key to independence and enjoyable living. To evaluate the effects of visual impairment among aging adults, the Purdue researchers used data from the Salisbury Eye Evaluation study. This longitudinal study included 2,520 older adults between the ages of 65 and 84 from the greater Salisbury, Md., area. Altogether, the researchers tracked the participants from September 1993 through July 2003, reassessing them at two, six, and eight years after the study began.

What did the researchers discover? Generally, declines in visual ability were linked to an increased risk of death due, in part, to decreasing levels of IADL. Compared to individuals with stable IADL levels, aging adults who experienced increasing difficulty with activities of daily living had an increased death risk: a three percent greater death risk annually and 31 percent greater death risk during the entire eight-year study period. In fact, participants who experienced an increase in visual impairment by just one letter on an acuity chart were expected to have a 16 percent increase in mortality risk during the study.

The researchers stated “the early detection of disabling eye diseases is suboptimal in the U.S. health care system" and unfortunately, this means many Americans are living with some visual impairment. Worse, these impairments might be corrected easily with glasses or contact lenses. Considering poor vision increases the risk of death, yearly eye exams could save lives.

Source: Christ SL, Zheng D, Bonnielin K, et al.  Longitudinal Relationships Among Visual Acuity, Daily Functional Status, and Mortality The Salisbury Eye Evaluation Study. JAMA Ophthalmology. 2014.