Wearing bifocals or progressive lenses may cause visual blurring. And that puts older people at risk of making a misstep and falling, researchers say.

The effects of blurry vision on stepping accuracy were greatest when study participants were looking ahead of where they were stepping, the findings showed.

The results serve as a reminder to watch your step, the researchers said.

Beyond that, “our findings … support the benefits of gaze training to maintain gaze position on stepping locations when undertaking precision stepping tasks,” wrote Alex Black and colleagues at Queensland University of Technology in Australia. Black suggested that this could improve stepping accuracy and minimize the risk of slips and trips.

For the study, the researchers asked 19 older adults, average age 72, to do a series of “precision stepping tasks” while wearing their normal glasses or glasses that produced blurred vision. For example, looking at a distance through bifocal or progressive (multifocal) lenses can cause blurred vision.

While the stepping errors made when wearing the blurred vision glasses were relatively small, the risk of falling may be high in places where proper foot placement is critical, such as on stairs or uneven surfaces, the study authors said.

The researchers suggested that it might be a good idea for some people — particularly active older adults — to use single-vision prescription glasses when walking.

The findings were published in the June issue of the journal Optometry and Vision Science.

“Falls for the elderly can be quite serious in consequence, so adopting strategies for avoiding falls is very important,” said journal associate editor Anthony Adams. “Our authors highlight the difficulty that bifocal and multifocal prescription glasses may create for the elderly, particularly if they gaze past the stepping point.”

More information

Learn more about how to prevent falls from the Health in Aging Foundation.

Source: HealthDay