by admin | Nov 29, 2023 | Dispensing
In 1962 the Optical Manufacturers Association adopted the boxing system to provide a standard for frame and lens measurement that greatly improved upon the accuracy of previous systems. The boxing system is based upon the idea of drawing an imaginary box around a lens...
by admin | Nov 28, 2023 | Dispensing
Visit OpticianWorks.com for the best comprehensive optician, ABO, and NCLE study programs. Depending on the equipment used by the doctor, a prescription may be in plus or minus cylinder form. For surfacing, the lab uses the minus form, meaning if a prescription is...
by admin | Nov 28, 2023 | Lens Options and Materials
Poly and Trivex: Facts and Fiction Even though Trivex has been available for years and polycarbonate for decades, there is still much debate, confusion and even long-held myths about how Trivex and polycarbonate stack up against one another. We'll lay out the facts,...
by admin | Nov 4, 2023 | Occular Anatomy
Visit OpticianWorks.com for the best comprehensive optician, ABO, and NCLE study programs. Major Ocular Structures The eye is made up of three layers: the outer layer called the fibrous tunic, which consists of the sclera and the cornea; the middle layer responsible...
by admin | Oct 30, 2019 | Lens Form and Theory
Normally, eyeglasses are fitted with the optical center of the lens directly in front of the eye. If the lens is fit off-center, image displacement can occur due to induced prism. The higher the power or the further the lens is fit off-center, the higher is the...
by admin | May 25, 2010 | Surfacing
The curvature of a progressive addition lens surface gradually increases toward the bottom of the lens, becoming increasingly steeper. This increase in curvature (and surface power) is what produces the add power of the progressive lens. Unfortunately, because the...
