The relationship between the accommodation accuracy as measured with the autorefractor and the total wavefront aberration as measured with a Hartmann-Shack wavefront sensor is largely influenced by the higher-order (fourth and above) aberration levels. For the emmetropic subjects, the errors measured by the two methods agree when adjusted to measure at similar pupil sizes. For the myopic subjects with similar pupil sizes, however, the Hartmann-Shack wavefront sensor underestimates the accommodation error at higher accommodation levels (2 to 4 D) compared with the autorefractor.

For reading tasks not involving eye movements, there is an advantage in eccentrically fixating such that text falls in inferior rather than left visual field.

When comparing findings between studies, the type of chart and the scoring method used may have a significant effect on the results obtained and should therefore be taken into consideration. Also, the additional time and effort demanded for determining a psychometric function for single readings of the Regan visual acuity chart is not rewarded with improved repeatability.