Visual Acuity

Degree of visual sharpness, as determined by a conformance to or deviation from the standard 20/20 measurement.

VDT (Video Display Terminal)

A term that refers to a specific type of glasses designed to be worn while working on the computer to address the different visual requirements and distance of the wearer. May also be referred to as occupational glasses and addresses a condition commonly referred to as computer vision syndrome. Usually VDT glasses are only covered as a second pair if they are ordered at the same time as the primary or main pair.

Utilization Review

The process of reviewing the appropriateness and quality of care provided to patients.

Ultraviolet Coating (UV)

A coating that blocks ultraviolet rays.


Lens that offers similar lightweight and impact resistant characteristics like polycarbonate but offers better clarity then poly due to higher Abbe value.

Trifocal Lens

See Lens, Trifocal.


Photochromic lenses that turn dark when exposed to the ultraviolet rays of the sun.

Tint, Solid

A lens dyed or coated with pigment of uniform color and density, which causes rays of light to be refracted.

Tint, Gradient

Tint is darker at the top and gradually lightens towards the bottom.


Normal tints that can be added to lenses to block between 5% and 20% of light. A darker tint is also available, which blocks up to 88% of light. The UV coating is always recommended with a sunglass tint. The most common tint colors are grey, green and brown.


The part of the frame attached to the frame front that runs along the side of the face and rests over the ears. Consists of the shaft, the bend and the earpiece.

Subjective Examination

An eye test using patients’ responses to help determine the prescription for glasses.


The prescription power, in diopters, that corrects for hyperobia or myopia.


Another term for eyeglasses. An ophthalmic device consisting of two ophthalmic lenses and a supporting frame to position and retain the lenses in proper optical alignment with the eyes.

Specialty Lenses (Myodisc, Lenticular Grind, Double Sided Grind)

See Lens, Specialty.

Slab Off

Used when there is a significant difference in powers for each eye on a patient’s prescription. Used when patient experiences a prismatic effect or image displacement due to anisometropia.


See Lens Size.

Single Vision Lenses

See Lens, Single vision.

Scratch Protection Plan

A warranty which ensures that if the coating does not prevent scratches it will be replaced at no additional charge.

Premium Scratch Resistant Coating

Extra-hard scratch resistant coating.

Skip to content