The Hidden Fall Risk of Bifocal Glasses
Why multifocal lenses matter for balance — and what older adults can do about it.
The problem: poor edge contrast and depth perception
Bifocal, trifocal, and progressive glasses combine multiple prescriptions in one lens. That convenience comes with a cost: the reading (add) portion of the lens reduces edge-contrast sensitivity and depth perception, exactly the visual cues an older adult needs to safely negotiate stairs, curbs, and uneven ground.
Looking down at a step through the near portion of the lens — or viewing an object at an angle so each eye is looking through a different segment — blurs the edge and distorts depth. Multifocal wearers routinely misjudge vertical toe clearance on stairs or clip the edge of a step.
How big is the risk?
- Older adults who wear multifocal glasses are 2.3× more likely to fall than those who wear single-vision glasses or no glasses.
- For elderly patients, more than one in three falls can be attributed to multifocal glasses.
- Providing single-vision distance glasses to habitual multifocal wearers has been shown to reduce falls by up to 40% among people who regularly spend time outdoors.
Why this matters for fall prevention
Vision is one of the risk factors we screen for in every assessment. A patient can do everything else right — strengthen their hips, clear their home hazards, review their medications — and still fall repeatedly because their lenses are quietly hiding the edge of the top step.
Because most falls happen close to home, and because stairs, thresholds, and curbs are exactly where multifocal glasses degrade vision most, a lens review with your eye doctor is one of the highest-leverage steps an older adult can take.
What you can do
- Talk to your ophthalmologist or optometrist about single-vision distance glasses for walking, stairs, and outdoor activity — and separate reading glasses for close work.
- Take glasses off, or switch to distance-only, on stairs. Never read your phone while descending.
- If you're planning cataract surgery, ask about lens options that could reduce your day-to-day reliance on multifocal glasses.
- Add vision to your fall-prevention plan. Annual eye exams are as important as annual physicals for adults over 65.
Source
Adapted with commentary from Daniel H. Chang, MD, "Balancing the Risks of Bifocal Glasses," CRST Europe, March 2020 — which summarizes the peer-reviewed literature including Lord SR et al., J Am Geriatr Soc 2002; Haran MJ et al., BMJ 2010; and Johnson L et al., Invest Ophthalmol Vis Sci 2007.