The Hidden Danger of Progressive Lenses

I am a healthy and physically fit 73-year-old. I exercise four or more days a week for at least an hour, and I’m strong and spry enough to chase, capture and tickle my five grandchildren. Even in my 60s, my doctor joked that I could probably still pass the Marine Corps physical.

So I was stunned to suffer not one or two but five serious falls this past year—two on staircases and three tripping over unseen obstacles and drop-offs right at my feet—landing me in the emergency room three times. The combined injury toll was a badly broken collarbone, a severely sprained ankle that put me in a boot for two months, a facial scar, two mild concussions and four staples to close a gash in my head.

The American Public Health Association (APHA) reports that a variety of health care organizations and governmental agencies recognize falls for adults 65 and over as an “urgent national public health crisis”; it’s the leading cause of injury-related deaths in people 65 and up, according to the Centers for Disease Control and Prevention. There’s a reason why some older adults take bad tumbles, and it’s not because we’re frail.

It’s because of our eyeglasses.

A prescription for falling down

Last November, the APHA urged the nation’s health professionals to carefully screen for patients at highest risk of falling, and identified 10 major causes contributing to the 3 million emergency room visits and 38,000 fall-related deaths among older adults, ­including medications, physical inactivity, dementia, neurological and metabolic disorders such as diabetes, and “vision impairment.”

What’s not spelled out is that when it comes to impaired vision and falls, the glasses themselves could be the danger: Several scientific studies have found that older people like me who wear multifocal eyeglasses—​progressives, bifocals or trifocals—to correct both near- and farsightedness were approximately twice as likely to suffer falls than those wearing single-vision lenses. A compilation of studies in the Journal of Refractive ­Surgery found that those with multifocal lenses are three times as likely to trip and fall when walking outside the home.

“As optometrists and ophthalmologists, we don’t see falling as a problem,” says ­Daniel H. Chang, M.D., a California ophthalmologist who wrote the study. “Because if the patient trips and falls, they don’t come and complain to us. They usually go to the hospital—or a funeral home.”

The reason those of us with multifocal lenses are at increased risk of falls is that these types of glasses make it harder to see the ground below us. This is not a new finding. The newsletter Harvard Women’s Health Watch summarized the multifocal problem in 2010: “When we walk, we normally see the ground from a distance of five-to-six feet, but the focal length of the lower segment of multi­focal lenses is only slightly more than one foot. Consequently, our view of the ground is … impaired at precisely the distance you need to detect and avoid ground-level obstacles.”

In the largest randomized controlled ­scientific trial to date, Australian researchers in 2010 tracked 606 people 65 and up who wore multifocals over 13 months. Among ­active people who went outside at least three times a week, those who switched to ­single-vision lenses for distance when walking outdoors fell 40 percent less than those who wore their multifocals, says Stephen Lord, senior principal research fellow at Neuro­science Research Australia and professor at the University of New South Wales, who conducted the study. He describes walking with multifocals instead of single-vision lenses as a form of “elective disability.”