Psychophysical estimates of the relative numbers of L- and M-cones

Method
Assumption
Study
Mean ratio (L/M cones)
Range of ratios
Photopic luminosity function Compares the relative numbers of L- and M-cones required to fit an indivdual or standard flicker photometric function. De Vries (1947)
--
0.59 - 4.0
Vos & Walraven (1971)
2.0
--
Walraven (1974)
2.0
--
Smith & Pokorny (1975)
1.6
--
Smith & Pokorny (1989)
--
0.50 - 10.0
Spectral acuity Compares visual acuities for heterochromatic gratings. Brindley (1954)
<< 1.0
--
Kelly (1973)
<< 1.0
--
Fundal reflectometry Compares the optical densities of the L- and M-cone pigments at 535 nm, following selective bleaches. Rushton & Baker (1964)
1.0
0.33 - 3.00
Weber fractions Compares the Weber fractions for Stiles' red and green p-mechanisms. Vos & Walraven (1971)
1.64
--
Spectral sensitivity functions Compares the relative heights of the spectral sensitivities of the cone primaries. Walraven (1974)
2.0
--
Point source detection Relates the steepness of the psychometric functions to the cone numbers contributing to detection. Cicerone & Nerger (1989)
2.07
1.46 - 2.36
Vimal et al. (1989)
2.8
1.6 - 4.0
Cicerone et al. (1994)
2.0
1.3 - 2.5
Human ERG Compares the amplitudes of the isolated L- and M-cone ERG responses. Shapley & Brodie (1993)
>>1.0
--

Compiled by Ted Sharpe.


References

Brindley, G.S. (1954). The order of coincidence required for visual threshold. Proceedings of the Physical Society, London B 67, 673-676.

Cicerone, C.M. & Nerger, J.L. (1989). The relative numbers of long-wavelength-sensitive to middle-wavelength-sensitive cones in the human fovea centralis. Vision Research 29, 115-128.

Cicerone, C.M., Gowdy, P.D. & Otake, S. (1994). Composition and arrangement of the cone mosaic in the living human eye. Investigative Ophthalmology & Visual Science 35 (supplement), 1571.

De Vries, H.L. (1947). The heredity of the relative numbers of red and green receptors in the human eye. Genetica 24, 199-212.

Kelly (1974). Spatio-temporal frequency characteristics of color-vision mechanisms. Journal of Physiology, London, 228, 55.

Rushton, W.A.H. & Baker, H.D. (1964). Red/green sensitivity in normal vision. Vision Research 4, 75-85.

Shapley, R.M. & Brodie, S. (1993). Responses of human ERG to rapid color exchange: implications for M/L cone ration. Investigative Ophthalmology & Visual Science 34 (supplement), 911.

Smith, V.C. & Pokorny, J. (1975). Spectral sensitivity of the foveal cone photopigments between 400 and 500 nm. Vision Research 15, 161-171.

Smith, V.C. & Pokorny, J. (1989). In: Proceedings of the AIC Wyszecki & Stiles Memorial Symposium on Colour Vision Models.

Vimal, R.L., Pokorny, J., Smith, V.C. & Shevell, S.K. (1989). Foveal cone thresholds. Vision Research 29, 61-78.

Vos, J.J. & Walraven, P.L. (1971). On the derivation of the foveal receptor primaries. Vision Research 11, 799-818.

Walraven, P.L. (1974). A closer look at the tritanopic convergence point. Vision Research 14, 1339-1343.