| Word | Definitions | Synonyms |
|---|---|---|
| dichromasy | (noun) a deficiency of color vision in which the person can match any given hue by mixing only two other wavelengths of light (as opposed to the three wavelengths needed by people with normal color vision) | Synonyms: dichromacy, dichromatism, dichromatopsia, dichromia |
| monochromasy | (noun) complete color blindness; colors can be differentiated only on the basis of brightness | Synonyms: monochromacy, monochromatic vision, monochromatism, monochromia |