(Clinically) Examination using a set of lenses to determine a patient's eyeglass prescription.
DISCUSSION
The refraction is the eye examination most patients are familiar with. A phoropter is placed in front of the patient's eyes and the patient is asked to read the smallest line they can on the eyechart, and then is asked to compare the clarity between progressive sets of lenses. The refraction can be done with the eyes in their natural state (manifest refraction) or with the ciliary muscle paralysed (cycloplegic refraction).
