Purpose. To investigate the subjective refraction techniques of UK optometrists and their influence on patient-reported problems with new spectacles. Methods. First, an investigation from optical practices’ perspective, with a study investigating the frequency and causes of patient complaints. Three questionnaires follow; i) quantification of patient-reported symptoms with new spectacles, ii) the methods of refraction used by clinicians and iii) part-refracting as a special case of part-prescribing. Finally, the typical cylinder changes prescribed in patients’ refractive history are examined. Results. 2.3% of eye examinations resulted in rechecks. Cylinders were implicated in 38% of causes, of which 42% were oblique. 83% of rechecks were due to inaccurate measurement of prescription; presenting symptoms, prescription changes and improvements in visual acuity (VA) were often not reconciled and 93% reported not measuring VA to full threshold. The change in ocular astigmatism from with- to against-the-rule with age was more than three times more likely to pass through oblique axes than a spherical prescription. 36% of eyes were found to have an oblique cylinder prescribed at least once and of these, 78% were transitory in nature. Conclusions. Subjective refraction, visual acuity measurement, analysis of refractive change and prescribing techniques were often poor and cylinder changes, particularly oblique, were identified as a cause of increasing rechecks with patient age. These are fundamental aspects of optometry, yet need to be more prominent in continuing professional development.