Plastic Photochromic Lenses

See Lens, Plastic photochromic.

Polarized Lenses

See Lens, Polarized.

Polaroid

Two lenses that are laminated to remove glare. Polaroid lenses are especially useful for boaters and pilots.

Polished Edge

A cosmetic service to make the sides of a cut lens look clear rather than a milky white. This service can be used on any minus lens and on most plus lenses. It is not beneficial to polish the edges of a lens when:

  • An Anti-Reflective Coating has been applied, because polished edges may let light in through the sides, which causes glare negating this feature.
  • Lenses are thin, in which case the polished sides can affect the structure of the lens.

Polycarbonate Lenses

See Lens, Polycarbonate.

Premium Scratch Resistant Coating

Extra-hard scratch resistant coating.

Presbyopia

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

Progressive Addition Lens

See Lens, Progressive.

PSPC (Professional Standards and Practices Committee)

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

Pupil

The dark opening in the center of the iris.

Pupil Distance (PD)

Measurement of the distance between the pupils.

Pupillary Distance, Monocular (MPD)

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

Quadrifocal Lens

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

Ray

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

Readables

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.

Readers

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

Refraction

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

Retina

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

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.

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.