title: The ratio of L cones to M cones in the human parafoveal retina.
abstract: We present psychophysically-based estimates of the relative numbers of long-wavelength-sensitive (L) and middle-wavelength-sensitive (M) cones in the parafovea of three color-normal trichromats. Using methods previously applied to the fovea centralis, we obtained estimates of the relative numbers of L and M cones at retinal eccentricities of 1.0, 1.5, 2.0, 3.0, and 4.0 deg along the horizontal meridian of the temporal retina. Results for three observers indicate that the L to M cone ratio remains approximately invariant from the fovea to 4.0 deg eccentricity, with a mean ratio near 2:1.
authors.affiliation: Department of Psychology, Colorado State University, Fort Collins 80523.
authors.forename: J L
authors.initials: JL
authors.lastname: Nerger
authors.forename: C M
authors.initials: CM
authors.lastname: Cicerone
mesh_terms: D002452:Cell Count; D003118:Color Perception / Q000502:physiology; D005260:Female; D005584:Fovea Centralis / Q000166:cytology; D006801:Humans; D008297:Male; D010786:Photoreceptor Cells / Q000166:cytology*; D011601:Psychophysics; D012160:Retina / Q000166:cytology*; D013053:Spectrophotometry