• Stephen R Lord, Julia Dayhew, and Amelia Howland.
• Prince of Wales Medical Research Institute, Randwick, University of New South Wales, Australia. S.Lord@unsw.edu.au
• J Am Geriatr Soc. 2002 Nov 1; 50 (11): 1760-6.

ObjectivesTo determine the extent to which multifocal glasses impair contrast sensitivity and depth perception at critical distances required for detecting hazards in the environment and whether multifocal glasses use increases the risk of falls in older people.DesignOne-year prospective cohort study.SettingFalls Laboratory, Prince of Wales Medical Research Institute.ParticipantsOne hundred fifty-six community-dwelling people aged 63-90.MeasurementsContrast sensitivity, depth perception, accidental falls.ResultsEighty-seven subjects (55.8%) were regular wearers of multifocal (bifocal, trifocal, or progressive lens) glasses. These subjects performed significantly worse in the distant depth perception and distant edge-contrast sensitivity tests in conditions that forced them to view test stimuli through the lower segments of their glasses. Multifocal glasses wearers were more than twice as likely to fall in the follow-up period than nonmultifocal glasses wearers (odds ratio (OR) = 2.29, 95% confidence interval (CI) = 1.06-4.92), when adjusting for age, poor vision, reduced lower limb sensation and strength, slow reaction time, and increased postural sway. Multifocal glasses wearers were also more likely to fall because of a trip (OR = 2.79, 95% CI = 1.08-7.22), when outside their homes (OR = 2.55, 95% CI = 1.14-5.70), and when walking up or down stairs (P <.01). The population attributable risks of regular multifocal glasses use were 35.2% for any falls, 40.9% for falls due to a trip, and 40.9% for falls outside the home.ConclusionsThe study findings indicate that multifocal glasses impair depth perception and edge-contrast sensitivity at critical distances for detecting obstacles in the environment. Older people may benefit from wearing nonmultifocal glasses when negotiating stairs and in unfamiliar settings outside the home.

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