Subjective Refraction

**Semantic type:** Diagnostic Procedure

**Definition:** A technique of determining the combination of spherical and cylindrical lenses that will result in the best-corrected visual acuity. The process involves the patient fixating at the Snellen Chart, while the clinician presents a variety of lenses and alters the power of the lenses in the trial frames according to the patient's subjective responses regarding improvements to their vision.

**Synonyms:** - SRF