Motion perception at mesopic light levels: effects of physiological ageing and eccentricity

Abstract

Purpose: To explore the differential effects of age and eccentricity on the perception of motion at photopic and mesopic light levels. Methods: Thirty-six visually normal participants (18 younger; mean age 25 years, range: 20–31) and (18 older; mean age 70 years, range: 60–79) underwent two testing sessions, one at photopic and one at mesopic light levels. In each session, motion perception was tested binocularly at two eccentricities (centrally, and peripherally at 15° rightwards and 5° superior to the horizontal) for four motion tasks: minimum contrast of a drifting Gabor to identify motion direction (motion contrast); translational global motion coherence; biological motion embedded in no..