Visual Pigment Gene Structure and the Severity of Color Vision Defects

Amino acid differences shift the spectral peaks of the L and M cone photopigments.

“amino acid differences that shift the spectral peaks of the L and M cone photopigments”

This deutan array structure is the one most commonly found in deuteranomalous males.

“This array structure is the one most commonly found in deuteranomlous males”

There is complete overlap between hybrid pigments mediating color vision in people with normal color vision and in people with red-green color vision deficiencies, although the frequencies of some hybrids are higher in color deficiency compared to normal trichromacy.

“there is complete overlap between hybrid pigments mediating color vision in people with normal color vision and in people with red-green color vision deficiencies, although the frequencies of some hybrids are higher in color deficiency compared to normal trichromacy (Carroll et al., 2002, Crognale, Teller, Motulsky & Deeb, 1998, Neitz et al., 1996, Sharpe et al., 1998, Winderickx et al., 1993).”

There is a very good correlation between deuteranomalous behavior in color vision tests and the magnitude of the spectral separation between the underlying L pigments; however, in some cases when people have very small spectral differences between their pigments, discrimination performance as measured by the range of anomaloscope settings accepted as a match is better than might be predicted from

“There is a very good correlation between deuteranomalous behavior in color vision tests and the magnitude of the spectral separation between the underlying L pigments; however, in some cases when people have very small spectral differences between their pigments, discrimination performance as measured by the range of anomaloscope settings accepted as a match is better than might be predicted from”

There is very good agreement between the deduced photopigment complement and color vision capabilities of people with color vision defects.

“There is very good agreement between the deduced photopigment complement and color vision capabilities of people with color vision defects (Barbur, Rodriguez-Carmona, Harlow, Mancuso, Neitz & Neitz, 2008, Neitz et al., 1996, Neitz et al., 2004, Shevell et al., 1998).”

X-chromosome opsin gene arrays underlying the dichromatic form, deuteranopia, either have a single opsin gene that encodes an L pigment, or have multiple genes in which the first two encode opsins that produce L pigments that are identical in spectra.

“X-chromosome opsin gene arrays underlying the dichromatic form, deuteranopia, either have a single opsin gene that encodes an L pigment, or have multiple genes in which the first two encode opsins that produce L pigments that are identical in spectra (Neitz et al., 1996).”