Free Form Lenses
What are free form lenses?
All free-form lenses are digital, but not all digital glasses lenses are free form.
A conventional eyeglass generator is capable of only cutting simple curves, meaning that the measurement of the curve is the same across the entire surface of the curve. Digital lens processing uses generators capable of cutting complex curves on the back surface of the lens. A complex lens curve is one in which the measurement of the curve changes across the surface of the curve. A sphere would have a simple curve, whereas an apple would have complex curves.
Free-form lens design is the process of using complex back surface curves to create a more accurate eyeglass lens design, whether it be for a single-vision design having much less peripheral distortion or to create an entire progressive design on the back surface of the prescription lens. These designs allow for more customization and personalization of the lenses, giving optical patients a lens that is made specifically for them. Prescription glasses lenses are no longer made to 0.10 or 0.12 diopter increments that are “close enough.” Patients can now have custom glasses lenses designed to take into account how the frame fits on their face, the ideal shape of the frame, and are made to 0.01 diopters of accuracy.
Rochester Optical’s line of free-form lenses includes the following:
- RO Versatile – Comparable to Shamir Autograph II, Hoya Array, and Seiko Supernal
- RO Digital – Comparable to Shamir Spectrum and Seiko Succeed
- RO Achieve – Comparable to Shamir Workspace, Autograph II Office, and Computer