1) Measurement of the pupil 
Pupillometry is the measurement of pupil a diameter in psychology. As mentioned in the paper of Laeng et al., this method established itself after the appearance of three seminal studies (Hess & Polt, 1960, 1964; Kahneman & Beatty, 1966). The method examines not only humans (including infants) but also animals, because pupillary responses occur fr...
Measurement of the pupil. ... (05 Mar 2000) ... 
(pu″pĭ-lom´ә-tre) measurement of the diameter or width of the pupil of the eye.
Type: Term Pronunciation: pyū′pi-lom′ĕ-trē Definitions: 1. Measurement of the pupil.
pupillometry The recording of the pupillary diameter of the eye.