Autorefractometry is an automated, objective method of measuring the eye’s refraction, which allows for the rapid determination of a vision defect without the need for the patient’s active participation in the examination. The device, known as an autorefractometer, emits a beam of infrared radiation, which, after passing through the eye’s optical system, is reflected from the retina and then analysed by the instrument’s detection system, enabling the calculation of the eye’s refractive power in various meridians. Most modern autorefractometers utilise the principle of automatic retinoscopy or the analysis of images of rings or light spots projected onto the retina. The result of the examination is given as three values: sphere (sph), cylinder (cyl) and the axis of astigmatism (axis), expressed in dioptres.
Autorefractometry provides a starting point for accurate subjective refraction testing and the selection of spectacle or contact correction, significantly speeding up the diagnostic process and reducing the time needed to accurately determine visual impairment. This method is particularly useful in the examination of children, people with communication difficulties, in screening eye examinations and as a preliminary examination before refractive surgery. However, it should be borne in mind that autorefractometry may be subject to accommodative error, especially in young patients, and that its results always need to be verified and possibly corrected during subjective visual acuity testing, as it does not take into account individual patient preferences or factors such as ocular prevalence or tolerance to correction.