scope:

This standard applies to all prescription dress ophthalmic spectacle lenses in edged or assembled form. It is a guideline for entities that fabricate, assemble or process dress eyewear or lens components. Relevant optical and physical specifications and tolerances of this standard also apply to uncut lenses.

This standard specifically excludes products covered by ANSI Z80.3, ANSI Z87, ANSI Z136.7, and sports and recreational protective eyewear covered within the ASTM F08.57 committee.

Purpose

This standard reflects the shift in utilization from mass-produced lenses to a basic dependence upon custom-processed lenses. It provides minimum acceptable tolerances for new lenses prepared to an individual prescription.

The power, prism, and axis tolerances established in this standard are subject to measurement limitations associated with the accuracy and repeatability of the current state-of-the-art focimetry and other measurements commonly in use by laboratory technicians and eyecare professionals. Users should therefore take into account the measurement capability of the devices (and methodology) when applying tolerances to the spectacle lens. As such, this voluntary standard expresses technical concepts that provide a frame of reference for safety and effectiveness. Refer to Annex F for additional guidance on this topic.