Wearing bifocal or multifocal glasses while walking — and looking too far ahead of where you are stepping — may cause potentially serious falls.
When you hit middle-age, sooner or later you’ll likely notice it’s harder to read menus and small print in books. Reading glasses can help correct these vision changes that come with age, a condition known as presbyopia. And most middle-aged and older adults need this type of vision correction.
You may opt for bifocal glasses that combine your regular glasses that allow you to see more clearly at a distance (the top part of the lens) with a magnifying reading glasses part on the bottom. For those who need vision correction to see things three to 20 feet away more clearly, multifocals, also called progressive lenses, have a middle part that helps intermediate sight.
These glasses are practical and save time. However, researchers found both bifocals and multifocals may pose a danger. Wearing them while walking and stepping up and down stairs, could raise the risk of stumbles and injury-producing falls, according to a study published in the American Academy of Optometry’s Optometry and Vision Science journal.
A research team at Queensland University of Technology in Brisbane, Australia, studied a group of 19 senior adults with normal vision while the volunteers performed a series of walking tasks, with and without looking through lenses that mimicked the “reading” part of bifocals and multifocals.
First, the researchers used a white marker to draw the contour of each participant’s dominant foot (the one they would use to kick a ball) on a gray floor. Yellow dots were also drawn on the floor one foot and two feet ahead of the target footprint.
Then study participants were asked to take a single step forward to place their foot as accurately as possible on the target footprint — first while looking at the yellow dot placed about a foot ahead of the target (an average step length) and then while gazing at the second yellow dot farther ahead. An eye-tracking device documented exactly where the volunteers were looking.
The research subjects carried out these tests wearing their normal glasses and then while wearing glasses designed to create the amount of blurred vision caused by looking at a distance through the bottom part of bifocal or multifocal lenses. How accurately the participants stepped into the outlined foot target was measured by digital photographs.
The results showed more foot placement errors occurred when the volunteers looked two feet ahead of the stepping target and when they wore the vision blurring glasses. While the errors weren’t huge, they were the kind of missteps that could translate into accidents during daily activities, resulting in falls from missing a step or stumbling over a curb.
Ophthalmology researcher Alex A. Black, PhD, who headed the study, and colleagues noted risks for falls are greater in situations where foot placement is critical for safety, "such as when negotiating stairs or uneven pavements, where even small errors in foot position may be enough to instigate a trip or fall."
The bottom line, especially for older adults, is to remember to literally “watch your step,” according to the researchers.
They advise focusing your gaze on where you are stepping — not many feet ahead — to minimize the risk of a tumble. Taking off your multifocal or bifocal glasses and wearing single-vision prescription glasses while walking could also help reduce the risk of falls.
"Falls for the elderly can be quite serious in consequence, so adopting strategies for avoiding falls is very important," said Anthony Adams, OD, PhD, associate editor of Optometry and Vision Science.
In fact, falls are the leading cause of fatal injury and the most common cause of non-fatal trauma-related hospital admissions for older adults, according to the National Council on Aging (NCOA). Every 11 seconds, an older adult is treated in the emergency room for a fall, and an older adult dies from a fall every 19 minutes.
Fortunately, most falls can be prevented. The NCOA offers tips for reducing the risk of falls and information on fall prevention programs.
November 17, 2016
Janet O’Dell, RN