Optical Terms and Definitions
given to describe the amount of chromatic aberration of a lens material.
Describes the clarity outside of the optical center. Higher ABBE, less
power/magnification required for near vision.
Anti-Glare, Anti-Reflective, AR
is a microscopically thin multilayer coating that
eliminates reflections from the front and back surface of eyeglass lenses.
cornea (the clear front cover of the eye) is irregularly shaped. Describes the
lack of ?roundness? of the cornea.
the angle of
your astigmatism correction.
lens deign that offers two different power corrections with a visible segment.
Generally has distance correction on the top and a segment for reading.
to a lens fabricated by computer controlled surfacing equipment. Offers better
acuity and better overall vision through the lens. Can result in a lens that is
thinner and lighter than non-digital lenses. In progressive lenses, can provide
fields of view 20% wider than non-digital lenses.
Drilled Rimless Frame
frame that requires drilling to hold the lens in place.
Fitting Height/ Seg Height/ OC Height
The vertical measurement from the bottom of the lens to the
center of the pupil.
sightedness. Trouble with far vision.
Latin terms for
righteye/left eye respectively. OD - oculus dextus. OS - Occulus Sinister.
eye care physician specialized in the treatment of eye disease, eye conditions
and eyesight correction.
eye care professional trained to measure and fit eyeglasses to the wearers
care professional trained to perform reflective eye exams, fit contact lenses
and assess overall eye health.
tint lens that can darken and lighted depending the amount of UV exposure
PhotoFusion A Zeiss
brand of photochromic feature.
polarized is a Sunglass lens with a layer in the material intended to reduce
glare and block reflections. Polarized lenses are not available in clear
Polycarbonate A strong,
lightweight, impact resistant material. A type of ophthalmic plastic.
condition caused by aging of the crystalline lens. Causes loss of near vision use. Prescription
will have an ADD power.
lens design that offers correction of multiple fields of view. Progresses from far vision correction at the
top, to near vision correction at the bottom of the lens. Corrects presbyopia.
opening of the iris. Dark center of the eye.
measurement between the pupils of you eyes. Can be measured pupil to pupil or
center of nose to each pupil.
property of the material that describes how it bends light. Higher index,
better refraction. High index lenses refract better than low index material and
therefore require less material to refract the same power; results in a thinner
types: 1. A frame that does not have an eye wire around the full perimeter of
the lens. Has an exposed edge on any side of the frame. 2. Requires a groove in
the lens to hold in place. Often look like a fully rimmed frame but requires a
Single Vision Lenses
lens design that offers the same power correction throughout the entire lens.
that starts clear and is dipped into a dye to create a fashion or sunglass
Transitions An Essilor brand of photochromic features.
lens deign that offers three different power corrections with a visible