Figure 1. Comparison of subjective refraction recorded by the subject’s own optometrist and non-cycloplegic autorefraction obtained at the 15-year ALSPAC research clinic. Whether the Avon Longitudinal Study of Parents and Children (ALSPAC) clinic record indicated that the subject was not wearing contact lenses during the autorefraction test is indicated by the symbol color. Note that the single outlying data point for the subjects confirmed as not wearing contact lenses corresponds to a myopic participant recorded as perfectly emmetropic by the optometrist, suggesting an error in data entry or retrieval instead of a highly inaccurate autorefraction measurement.