瞳距

tóngjù
pupillary distance (PD)

CEDICT

  1. (anatomy) pupillary distance
  2. pupillary distance

Wiktionary

Entry Composition

1 瞳 tóng pupil of the eye
2 距 jù
  1. to be at a distance of ... from; to be apart from
  2. (bound form) distance
  3. spur (on the leg of certain birds: gamecock, pheasant etc)