Contributed talks II: Sensitivity to temporally modulated defocus for different monochromatic stimuli

Programmable lenses allow for the measurement of quick changes in optical power. In a previous study we reported the temporal defocus sensitivity function, which measures the just noticeable defocus change for different temporal frequencies for an achromatic stimulus. Here we extend this measurement to different colors. A tunable lens (Optotune) was used to induce temporal defocus variations. An AMOLED display (Waveshare) was used to measure red, green, and blue stimuli with narrow (spectral width at half of 35nm) and separated components (625, 530, 460nm). An achromatic (white on black) stimulus was also measured. All colors were equiluminant. A staircase procedure was used to find the just noticeable defocus change for different temporal frequencies (from 0.5 to 35Hz) using a 4cpd Gabor patch in 3 young subjects. The just noticeable defocus for all temporal frequencies were fit to a model of temporal defocus perception to determine the maximum sensitivity and the defocus critical fusion frequency (DCFF) for each color component. Averaged across subjects, the maximum sensitivity was below 0.1D for each color, with little differences among them. However, the DCFF was lower for blue (22 Hz) and red (26 Hz) stimuli than for green and white (35 and 36Hz, respectively). Red and blue stimuli and white and green stimuli were highly correlated (r2=0.71 and 0.99, respectively). These results are relevant for emerging technologies that make use of temporal changes in optical power.