A United States Navy optometrist technician using an<unk>  during a humanitarian assistance project in Nicaragua in 2008 An<unk>  or automated refractor is a computer-controlled machine used during an eye examination to provide an objective measurement of a person's refractive error and prescription for glasses or contact lenses. This is achieved by measuring how light is changed as it enters a person's eye.
Autorefractor
Autoinjector
Lensmeter
Thalamic stimulator
Pupilometer
Focometer
Oculocardiac reflex
Retrobulbar block