OBJECTIVES: To determine whether wearing multifocal glasses affects obstacle avoidance and eye and head movements during walking with and without a secondary visual task in older people.
DESIGN: Randomized order, cross‐over, controlled comparison.
SETTING: Falls laboratory, medical research institute.
PARTICIPANTS: Thirty community‐living adults aged 65 and older.
MEASUREMENTS: Obstacle contacts, secondary‐task errors, average head angle (HA) in pitch, and peak‐to‐peak pitch amplitude of the eye (PA‐E) and the head (PA‐H) were assessed during obstacle‐only and dual‐task trials that required participants to read a series of letters presented in front of them at eye level under multifocal and single‐lens glasses conditions.
RESULTS: When wearing multifocal lens glasses, participants performed the obstacle‐only trials more slowly (P=.004) and contacted more obstacles in the dual‐task trials (P=.001) than when wearing single‐lens glasses. For the dual task trials under the multifocal glasses condition, greater PA‐E was associated with more obstacle contacts (ρ=0.409, P=.02) and greater PA‐H was associated with more secondary‐task errors (ρ=0.583 P=.002). Lower HA was associated with more secondary‐task errors (ρ=0.608, P=.002) and increased PA‐H (ρ=0.426, P=.02).
CONCLUSION: The findings demonstrate that older adults contact more obstacles while walking with their attention divided when wearing multifocal glasses. This is probably because of a failure to adopt a compensatory increase in pitch head movement, resulting in blurred vision of obstacles viewed through the lower segments of multifocal glasses.
", language="", issn="0002-8614", doi="10.1111/j.1532-5415.2009.02436.x", url="http://dx.doi.org/10.1111/j.1532-5415.2009.02436.x" }