noun
color vision deficiency; color blindness
Medical term for conditions where color perception is impaired. In everyday conversation, 色盲 (しきもう) is also used, but 色覚異常 is the more precise clinical term.
色覚異常は遺伝による場合が多い。
Color vision deficiency is often hereditary.
Because of his color vision deficiency, he has difficulty distinguishing red and green.