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

Purpose To explore the differential effects of age and eccentricity on perception motion at photopic mesopic light levels. Methods Thirty-six visually normal participants (18 younger; mean 25 years, range: 20–31) older; 70 60–79) underwent two testing sessions, one In each session, was tested binocularly eccentricities (centrally, peripherally 15° rightwards 5° superior to horizontal) for four tasks: minimum contrast a drifting Gabor identify direction (motion contrast); translational global coherence; biological embedded in noise duration high-contrast determine motion, using sizes measure spatial surround suppression motion. Results There significant main effect condition (higher thresholds mesopic) (p < 0.001), = 0.001) 0.001); older adults) 0.04) peripherally) 0.001). Additionally, we found three-way interaction between levels, (similar increase centrally both groups, but much larger deterioration adult’s peripheral thresholds, p 0.02). Finally, two-way values central relative photopic, Conclusions For majority tasks assessed, reduced conditions, similar extent groups. However, because some adults exhibited elevated even under particularly periphery, ability detect moving stimuli high markedly impaired individuals. Our results imply age-related differences detection night that might impact hazard avoidance driving ability.