Three Things You Need to Know About Free Form Lens Quality Control

An abstract to the whitepaper, “Understanding HOYA’s iD Lens Series Quality Card.”

One - There Was a Time When Two Was Enough In past years, progressive lenses were produced using molded semi-finished blanks, and by surfacing spherical or toric surfaces onto the back of the lens. The design of the lens was incorporated into the molded lens blank at the factory, and the conformance of the molded progressive to the design was assured by inspecting the blanks during the lens casting process. After surfacing in the laboratory, the final Rx was verified by checking power at two points – the Distance and Near Verification circles. This process, which has been widely used since the introduction of progressive lenses, delivers predictable quality, and can be easily verified by ECP’s by use of a lensometer.

Two – Free-Form Changes Everything Since lenses produced using Hoya Free-Form processing techniques do not use factory molded surfaces, the laboratory that produces the lens must assume the entire role of quality assurance. HOYA Free-form quality assurance means more than verifying power in the Distance and Near Verification circles. The purpose of the HOYA inspection process is to guarantee the design integrity over the entire surface of the lens.

Three – Not All Quality Control Processes Are the Same Other competing lens designs may use Free-Form surfacing techniques to produce advanced curves and corrections, but many still only verify the lens at the Distance and Near Verification circles, and do not make use of lens mapping. Unfortunately, there are many production errors that could allow a lens to look within tolerance in those two places, but fail to deliver the intended design at other places in the lens. In those cases, the fabrication process has failed to maintain the integrity of the design, and will deliver a non-optimal visual experience to the patient.

For more information about free form lens quality control processes you request a copy of the complete whitepaper by emailing us at, or your local HOYA representative would be happy provide you and your team a lunch and learn presentation.