The aim of this work was to investigate the contrast sensitivity function for sine-wave gratings in the range between 0.25-2 cpd in young and older adults (20-23, 30-39, 40-49, 50-59, 60-69 years old) using low luminance. All subjects were free from identifiable ocular disease and had normal acuity. We measured the contrast thresholds for 30 participants (six volunteers in each age) using the psychophysical forced-choice staircase method. In this method the volunteers had to choose the stimulus containing a test frequency at low contrast (e.g., a sine-wave grating), or another neutral stimulus at mean luminance (0.7 cd/m²). The results showed significant changes of CSF for sine-wave gratings at 1 and 2 cpd for the adults 50-59 and 60-69 years old compared to the adults of 20-23 years old. These results suggest age-related changes in the CSF for sine-wave grating at low luminance levels.
Visual perception; contrast sensitivity; aging; spatial frequency; forced-choice staircase method
