Proper functioning of sensory systems requires the generation of appropriate numbers and proportions of neuronal subtypes that encode distinct information. Perception of color relies on signals from multiple cone photoreceptor types. In cone-dominated retinas, each cone expresses a single opsin type with peak sensitivity to UV, long (L) (red), medium (M) (green), or short (S) (blue) wavelengths...

PURPOSE To study the relationship between cone spacing and density and clinical measures of visual function near the fovea. METHODS High-resolution images of the photoreceptor mosaic were obtained with adaptive optics scanning laser ophthalmoscopy from 26 patients with inherited retinal degenerations. Cone spacing measures were made close to or at the foveal center (mean [SD] eccentricity, 0....

PURPOSE Normal color vision depends on normal long wavelength (L), middle wavelength (M), and short wavelength sensitive (S) cones. Hereditary "red-green" color vision deficiency (CVD) is due to a shift in peak sensitivity or lack of L or M cones. Hereditary S cone CVD is rare but can be acquired as an early sign of disease. Current tests detect CVD but few diagnose type or severity, critical f...

The distinctive red-green dimension of human and nonhuman primate color perception arose relatively recently in the primate lineage with the appearance of separate long (L) and middle (M) wavelength-sensitive cone photoreceptor types. "Midget" ganglion cells of the retina use center-surround receptive field structure to combine L and M cone signals antagonistically and thereby establish a "red-...

Estimates of the density spectrum of the macular pigment (Wyszecki G, Stiles WS. Color Science: Concepts and Methods. Quantitative Data and Formulas. 1st ed. New York: Wiley, 1967); (Vos JJ. Literature review of human macular absorption in the visible and its consequences for the cone receptor primaries. Institute for Perception. Soesterberg, The Netherlands, 1972) are partially based on the di...

Under dim background conditions, the S-cones make little or no contribution to luminance (A. Eisner & D. I. MacLeod, 1980; W. Verdon & A. J. Adams, 1987), yet under conditions of intense long-wavelength adaptation, a small but robust contribution to luminance--as defined by heterochromatic flicker photometry (A. Stockman, D. I. MacLeod, & D. D. DePriest, 1987, 1991) or motion (J. Lee & C. F. St...

Cone signals in the luminance or achromatic pathway were investigated by measuring how the perceptual timing of M- or L-cone-detected flicker depended on temporal frequency and chromatic adaptation. Relative timings were measured, as a function of temporal frequency, by superimposing M- or L-cone-isolating flicker on "equichromatic" flicker (flicker of the same wavelength as the background) and...

This paper incorporates cones on virtual multipliers of inputs and outputs into DEA analysis. Cone DEA models are developed to generalize the dual of the BCC models as well as congestion models. Input-output data and/or numbers of DMUs for BCC models are inadequate to capture many aspects where judgments, expert opinions, and other external information should be taken into analysis. Cone DEA mo...