The most popular type of high-definition eyeglass lenses are called free-form lenses. The term "free-form" refers to an advanced manufacturing process that reduces higher-order aberrations such as spherical aberration that occur in eyeglass lenses created with traditional eyeglass lens manufacturing tools and processes.
With free-form lenses (also called digital high-definition lenses), the fabrication of the lenses from wearer's eyeglass prescription is optimized with computer-controlled surfacing equipment that is much more precise than conventional tools.
In fact, free-form technology can surface lenses in power increments of 0.01 diopter (D), compared with 0.125 to 0.25 D increments of conventional eyeglass lens tooling.
The fabrication of some digital, free-form lenses also takes into account how the lenses are positioned in front of the wearer's eyes when in the eyeglass frame, to provide the most accurate lens power and the sharpest vision possible.
Other factors that may be considered in the lens customization process include the angle between the eye and the back surface of the lens in different gaze positions (for example, when the wearer is looking off to the side rather than straight through the center of the lens), the frame size and the position of the wearer's pupil within the frame outline.
With these and possibly other factors taken into account during lens design and fabrication, high-definition eyeglass lenses offer an unprecedented degree of customization and may reduce or eliminate certain higher-order aberrations.
The precisely made and personalized surfaces of high-definition lenses may help reduce aberrations that limit field of view and cause starbursts, halos and comet-shaped distortions of lights at night.
The result is that high-definition lenses may provide sharper image quality, better peripheral vision, improved contrast sensitivity and less glare at night.
HB Optical Laboratories
Full service digital laboratory with an ARC facility.
Anti-reflective coating, conventional lenses and Free-Form lenses.