OPTOGRAM
Op"to*gram, n. Etym: [Optic + -gram: cf. F. optogramme.] (Physiol.)
Defn: An image of external objects fixed on the retina by the photochemical action of light on the visual purple. See Optography.
OPTOGRAPHY
Op*tog"ra*phy, n. Etym: [Optic + -graphy.] (Physiol.)
Defn: The production of an optogram on the retina by the photochemical action of light on the visual purple; the fixation of an image in the eye. The object so photographed shows white on a purple or red background. See Visual purple, under Visual.
OPTOMETER
Op*tom"e*ter, n. Etym: [Optic + -meter.] (Physiol.)
Defn: An instrument for measuring the distance of distinct vision, mainly for the selection of eveglasses.
OPTOMETRIST
Op*tom"e*trist, n.
Defn: One who is skilled in or practices optometry.
OPTOMETRY
Op*tom"e*try, n.
1. (Med.) Measurement of the range of vision, esp. by means of the optometer.