Medical term:
achromatopsia
ach·ro·ma·top·si·a
, achromatopsy (ă-krō'mă-top'sē-ă, a-krō'mă-top-sē), [MIM*216900, MIM*262300 & MIM*603096]The complete form of achromatopsia, characterized by severe deficiency of color perception, associated with nystagmus, photophobia, reduced visual acuity, and "day blindness"; is of autosomal recessive inheritance. One form, Achromatopsia type 1, maps to chromosome 14. Achromatopsia type 2 is caused by mutation in the cone photoreceptor cGMP-gated cation channel, alpha-subunit 3 gene (CNGA3) on chromosome 2q. Achromatopsia type 3 is caused by mutation in the CNGB3 on 8q.
Synonym(s): achromatic vision, monochromasia, monochromasy, monochromatism (2)
[G. a- priv. + chrōma, color, + opsis, vision]
Farlex Partner Medical Dictionary © Farlex 2012
achromatopsia
The formal term for what is popularly termed colour blindness, for a number of clinical syndromes which may be acquired (colour agnosia and cerebral achromatopsia) or inherited (e.g., autosomal recessive), in which the retinal cones and neural fibres conducting the information are intact, but the signal does not process.Clinical findings
Achromatopsia, nystagmus, amblyopia, photophobia, hemeralopia and pupillary irregularities.
Colour blindness/achromatopsia may be
(1) Complete (or total), or
(2) Partial (or incomplete), with a quantitative reduction of one or more attributes of the perception of colour—e.g., brightness, hue, saturation.
Achromatopsia
A generic term which encompasses a number of clinical syndromes which may be acquired—colour agnosia and cerebral achromatopsia—or inherited—autosomal recessive—and in which the retinal cones and neural fibres conducting the information are intact, but the processing of the signals is not.Clinical findings Achromatopia, nystagmus, amblyopia, photophobia, hemeralopia and pupillary irregularities.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
ach·ro·ma·top·si·a
, achromatopsy (ă-krō-mă-top'sē-ă, ă-krō'mă-top-sē)A severe congenital deficiency in color perception, often associated with nystagmus and reduced visual acuity.
Synonym(s): achromatic vision, monochromatism (2) .
Synonym(s): achromatic vision, monochromatism (2) .
[G. a- priv. + chrōma, color, + opsis, vision]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
achromatopsia
A rare but severe defect of colour vision in which the world is perceived almost in monochrome.Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Achromatopsia
The inability to distinguish any colors.
Mentioned in: Color Blindness
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
Achromatopsia
Total colour blindness. The majority of cases are autosomal recessively inherited and caused by a mutation in genes CNGA3, CNGB3 and CNAT2. There are two types of achromatopsia. Complete achromatopsia which results from having only rods and no functional cones (rod monochromat) have photophobia, poor acuity and nystagmus. Incomplete achromatopsia in which there are the same symptoms, but in a diminished form. Patients benefit from dark tinted lenses. Achromatopsia is non-progressive and very rare: one person in about 35 000 people. A few cases may be acquired resulting from a lesion in cortical area V4 (central achromatopsia). Syn. achromasia; achromatic vision; achromatism; acritochromacy; monochromatism. See defective colour vision; hemiachromatopsia; monochromat.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
ach·ro·ma·top·si·a
, achromatopsy (ă-krō-mă-top'sē-ă, ă-krō'mă-top-sē) [MIM*216900, 262300 & 603096]A severe congenital deficiency in color perception, often associated with nystagmus and reduced visual acuity.
Synonym(s): monochromatism (2) .
Synonym(s): monochromatism (2) .
[G. a- priv. + chrōma, color, + opsis, vision]
Medical Dictionary for the Dental Professions © Farlex 2012
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