A new system of refraction for use by the general practitioner.
D000328:Adult; D000367:Age Factors; D002648:Child; D011307:Drug Prescriptions; D005194:Family Practice; D006801:Humans; D008875:Middle Aged; D009907:Optometry / Q000295:instrumentation / Q000379:methods*; D012030:Refractive Errors / Q000175:diagnosis*; D013019:South Africa