Definition of protanopia in US English:

protanopia

noun

  • Color-blindness resulting from insensitivity to red light, causing confusion of greens, reds, and yellows. It is hereditary and is the most common form of color-blindness.

    Also called daltonism
    Compare with deuteranopia, tritanopia
    • ‘Someone pointed out to us yesterday that the current things colour scheme is far from ideal if you suffer from protanopia, deutanopia or tritanopia - colour blindness.’
    • ‘The genetic cause has been determined for several color vision defects, achromatopsia (the loss of all color vision), blue monochromatism, protanopia, deuteranopia, and enhanced S-cone syndrome.’

Origin

Early 20th century: from proto- ‘original’ (red being regarded as the first component of colour vision) + an- ‘lacking’ + -opia.

Pronunciation

protanopia

/ˌprōdəˈnōpēə/