Hello all,

Why is refraction distance not a standard measurement listed on Rx's in the US? With the increasing use of compensated lens designs that rely on position of wear measurements why are refraction distances not more commonly recorded, or shared by optometrists? Without knowing the refraction distance, how can we accurately calculate vertex distance and lens tilt/wrap compensations? I would think especially for those high power >+/-10.0D wearers it would be a given for better optics, and more closely align with the intended optical correction. Without how do we really know if something is within ANSI tolerance? It could be in tolerance of 13mm, but what about 10mm?

The point being, accurate measurements give accurate results, and if the measurements we use are averages or standards, the lenses will be just that. I realize that refractions can be subjective, in that phoropter distance can vary, pupil sizes differ, responses can vary by person, and diopters are prescribed in 0.25 increments, but with current technology shouldn't we strive for more precision, and less subjectivity?