Clinical evaluation of the 6600 Autorefractor.

The 6600 Autorefractor was evaluated on 200 patients undergoing refraction. The automatic refractor showed a high degree of accuracy in determining the needed refractive correction, but the errors are sufficient that the automatic refractor alone without subjective refinement cannot be substituted for conventional complete refracting methods with subjective refinement. However, for aphakic patients and for patients with clear media and cylindric corrections over 0.50 diopters, the automatic refractor can be used as a substitute for retinoscopy in determining the starting point for a subjective refraction.