The difference between belief and reality for Viktorin's method of inter-pupillary distance measurement.

摘要

The variation in the measurement of an inter-pupillary distance and monocular centration distance by 54 registered practitioners using a 'pd rule' was investigated. Their estimate of the repeatability of the measurement was also recorded, as was any correction for their own inter-pupillary distance. There was found to be considerable variation between practitioners in all measurements, and the practitioners' estimated repeatability of the measurement was rather better than the reality.