title: Design of a trichromatic cone array.
abstract: Cones with peak sensitivity to light at long (L), medium (M) and short (S) wavelengths are unequal in number on the human retina: S cones are rare (<10%) while increasing in fraction from center to periphery, and the L/M cone proportions are highly variable between individuals. What optical properties of the eye, and statistical properties of natural scenes, might drive this organization? We found that the spatial-chromatic structure of natural scenes was largely symmetric between the L, M and S sensitivity bands. Given this symmetry, short wavelength attenuation by ocular media gave L/M cones a modest signal-to-noise advantage, which was amplified, especially in the denser central retina, by long-wavelength accommodation of the lens. Meanwhile, total information represented by the cone mosaic remained relatively insensitive to L/M proportions. Thus, the observed cone array design along with a long-wavelength accommodated lens provides a selective advantage: it is maximally informative.
authors.affiliation: Department of Psychology, Saint Joseph's University, Philadelphia, Pennsylvania, USA. patrick.garrigan@sju.edu
authors.forename: Patrick
authors.initials: P
authors.lastname: Garrigan
authors.forename: Charles P
authors.initials: CP
authors.lastname: Ratliff
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Klein
authors.forename: Peter
authors.initials: P
authors.lastname: Sterling
authors.forename: David H
authors.initials: DH
authors.lastname: Brainard
authors.forename: Vijay
authors.initials: V
authors.lastname: Balasubramanian
mesh_terms: D000465:Algorithms; D019295:Computational Biology / Q000379:methods*; D016208:Databases, Factual; D006801:Humans; D008027:Light; D008954:Models, Biological; D010781:Photography; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*