What does achromatopsia mean?
Achromatopsia is a rare inherited disorder of the retina in which the cone photoreceptors responsible for colour vision do not function normally or are absent. As a result, a person with the condition cannot perceive colour and generally sees the world in shades of grey. The condition also commonly causes reduced visual acuity and sensitivity to bright light. Achromatopsia is not simply another name for the familiar difficulty some people have in distinguishing red from green; it denotes the much rarer and more complete absence of colour perception. In medical writing, the word is used precisely to identify this inherited retinal disorder, while the related adjective achromatopsic describes a person or condition associated with it. The term is useful because it distinguishes a highly specific diagnosis from the broad category of colour-vision deficiency and highlights how profoundly the condition can affect visual experience.
nounA rare inherited retinal disorder in which functional cone photoreceptors are absent, resulting in no colour perception, reduced visual acuity, and marked sensitivity to light. The visual world is perceived in shades of grey rather than in colour.
- A rare inherited retinal disorder caused by the absence of functional cone photoreceptors, producing an absence of colour perception, reduced visual acuity, and photophobia.
"The diagnosis of achromatopsia was confirmed after the patient's visual acuity and colour-vision tests were reviewed."
"Researchers are investigating gene therapy for children born with achromatopsia."
"The ophthalmologist explained that achromatopsia would require special tinted lenses and support with navigation and reading."
The plural is uncommon in general use; writers often refer to cases of achromatopsia instead.
"Rare achromatopsias have been documented in communities with a high prevalence of inherited eye disorders."
In achromatopsia, the retina's colour receptors are not functioning, so the world appears without colour—often in shades of grey.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does achromatopsia come from?
The word was formed in modern medical Latin from Greek-derived elements meaning “without colour” and “vision”. Its components correspond to the Greek roots a-, meaning “without,” chroma, meaning “colour,” and opsia, meaning “sight” or “appearance.” It belongs to a wider family of colour and light words that includes chromatic, achromatic, and monochromatic.
Related word forms
How achromatopsia is actually used
This is a specialised medical term, normally used in clinical or scientific contexts. It is more specific than the general expression colour blindness and should not be used as a synonym for every form of impaired colour perception.
Easily confused with achromatopsia
Colour blindness is a broad term for impaired colour discrimination, often involving difficulty distinguishing red and green, whereas achromatopsia is the specific inherited condition in which colour perception is absent.