Quote:
When examining patients for the eye test I always have difficulty measuring the back vertex distance. By definition its the ditance from corneal apex to the backmost trial lens in the trial frame but when it comes to measuring with accuracy I fail. Is it measured with both examiner eyes opened with examiner standing to the side of the patients face. How is it measured for trial frames.
most phoropters have this built in so I never really worried about it.. but as for a trial frame I always measured it from the side with a PD stick..