Scotopia

Part of speech: noun

Definitions

1. The condition of the eye when adapted to very dim light, in which vision relies mainly on rod cells rather than cone cells
2. The visual state of the eye in darkness, when perception depends on rods and colour is largely lost
3. Vision adapted to low illumination, a dark-adapted state of the eye in which only shades of grey are perceived clearly

Etymology: Scotopia is a coinage of the early twentieth century, not an ancient term. It was probably made by the British ophthalmologist John Herbert Parsons (1863–1957), who first put it into print in a 1912 journal article. The form is built from two Greek-derived pieces: "scoto-", meaning darkness, and "-opia", meaning vision. Parsons was describing the eye's switch to dim light, when the cones that handle colour stop working and only shades of grey remain distinct. The first half comes from Ancient Greek "skotos", meaning darkness or gloom. Greek scholars would have recognised the root, but nobody in antiquity used it for the eye. The second half comes from the Greek "ops", meaning eye or sight, which appears in many medical words, such as "myopia" and "presbyopia", that were likewise coined from classical roots in modern times.

Synonyms: night vision