How does an autorefractor work?

Q: How does an autorefractor work?

A: The automated refractor displays an image into the eye. The infrared light rays from the image then pass through

the autorefractor lens and strike the retina. Light rays get reflected from the retina, the eye, and pass through the

optical lens. The defectiveness in the eye lens distorts and defocuses the reflected image. The autorefractor senses

these defects/imperfections. 

The instrument then uses its lenses and software to rectify the returned image until no imperfections remain. This

process is carried out thrice, and the autorefractor’s software provides the corrected lens prescription for the eye.

The automatic refractor is used for measuring the axial, spherical, and cylindrical lens components.