Autorefractor

An autorefractor 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.

The majority of autorefractors calculate the vision correction a patient needs (refraction) by using sensors that detect the reflections from a cone of infrared light.

These reflections are used to determine the size and shape of a ring in the retina which is located in the posterior part of the eye.

Retinoscopy performed by an experienced clinician has been found to provide a more accurate estimation of refractive error than autorefraction.

[2] Recent studies report that autorefractor measurements without application of cycloplegia medication can result in significant overestimation of myopia.