title: Accommodation responds to changing contrast of long, middle and short spectral-waveband components of the retinal image.
abstract: We simulated the effects of longitudinal (axial) chromatic aberration and defocus on contrast of the long-, middle- and short-wavelength components of the retinal image to determine whether the effects of chromatic aberration are sufficient to drive accommodation. Accommodation was monitored continuously while subjects (12) viewed a 3 c/deg white sine-wave grating (0.92 contrast) in a Badal stimulus system. The contrasts (amplitudes) of the red, green and blue components of the white grating changed independently to simulate a grating oscillating from 1 D behind the retina to 1 D in front of the retina at 0.2 Hz. Subjects responded strongly to the chromatic simulation but poorly to a luminance control. The results support the hypothesis that focus is specified by the contrast of spectral-wavebands of the retinal image, and that conventional color mechanisms, monitoring chromatic contrast at luminance borders (1-8 c/deg), mediate the signals that specify dioptric vergence.
authors.affiliation: Schnurmacher Institute for Vision Research, State College of Optometry, State University of New York, NY 10010, USA.
authors.forename: P B
authors.initials: PB
authors.lastname: Kruger
authors.forename: S
authors.initials: S
authors.lastname: Mathews
authors.forename: K R
authors.initials: KR
authors.lastname: Aggarwala
authors.forename: D
authors.initials: D
authors.lastname: Yager
authors.forename: E S
authors.initials: ES
authors.lastname: Kruger
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D003118:Color Perception / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology; D013053:Spectrophotometry; D013997:Time Factors