Subjective measures of refractive error were obtained on 530 eyes using the AO SR III Subjective Refraction System (operated by a trained secretary) and using a phoropter (operated by optometrists and optometry students) in a clinical setting. Comparison of these measures from the present study and from a previous study by Bannon leads us to conclude that the SR III instrument is capable of estimating refractive error with good agreement with conventional refractive methods. Comparison with the Acuity Systems' 6600 Auto-Refractor(tm) was also made.