Refraction Test definition
Refraction Test is a diagnostic procedure to measure REFRACTIVE ERRORS of the EYE, such as MYOPIA, HYPEROPIA, and ASTIGMATISM. An optometrist or ophthalmologist conducts the test using a device called a refractor. The refractor fits against the face somewhat like a flattened pair of binoculars, with a chin rest and forehead pad to support the head in proper position.
After covering one eye, the eye professional applies combinations of lenses to the eye piece. The person looks through the eye piece and lens at a rendition of the SNELLEN CHART. The eye professional examines first one eye with the other eye covered, switches eyes, and finally examines both eyes together to confirm the appropriate refractive correction.