Scratch Resistant Coating

Many lenses manufactured today automatically come with a basic scratch resistant coating. Although scratch resistance does not mean 100% scratch proof, it can help to prevent minor scratches that can occur with daily wear. This is different from the Scratch Protection Plan offered by Davis Vision.

Safety Glasses

Protective eyeglasses with a minimum lens thickness of 3.0mm (1mm thicker than conventional lenses). Special (stronger) frames must be used instead of conventional dress frames.

Roll Edge

Same as above without the polish.

Roll and Polish

A rolled edge is created when the edge of a lens is beveled down to reduce edge thickness. Edge is then polished for cosmetic purposes. Getting an edge polished is strictly the wearer’s preference.

RLX Coating

Scratch-Resistant coating.

Rimless Drill

Frame in which the lenses are drilled into to attach the nasal and temple parts of the frame. Lenses serve as the shape of the frame.

Retinal Imaging

Takes a digital picture of the back of your eye. It shows the retina (where light and images hit), the optic disk (a spot on the retina that holds the optic nerve, which sends information to the brain), and blood vessels.


The thin transparent membrane in back of the eye. The light-receptive portion of the eye.


Loosely referred to as an eye examination (brief eye examination). The measuring of visual acuity and required correction.


Varilux® reading lenses with an expanded visual range that provides an extra-close range at the bottom of the lens. Ideal for single vision reading lenses. Also available in Varilux® bifocal.


Reading glasses that are worn to help with reading or other near vision tasks.


A straight line representing the direction of a ray or bundle of rays of light. An element of geometrical optics.

Quadrifocal Lens

A spectacle lens with different powers in four different segments, typically for occupational use.

Pupillary Distance, Monocular (MPD)

The measurement from the center of the nose to the pupil.

Pupil Distance (PD)

Measurement of the distance between the pupils.


The dark opening in the center of the iris.

PSPC (Professional Standards and Practices Committee)

The PSPC sets clinical standards of practice and evaluates conformance with existing protocols, making modifications when necessary.

Progressive Addition Lens

See Lens, Progressive.


A reduction in accommodative ability. This occurs normally with age and causes the need for bifocal eyewear.

Polycarbonate Lenses

See Lens, Polycarbonate.

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