Optical Education Library

ABO Study

Free ABO Study Guide AND Review Quizzes

The NEW updated Ultimate ABO Study ebook is now available for instant download via FREE membership on our optician education site, OpticianWorks.com along with greatly expanded and improved review tests. With you free membership you will also have access to 15 Steps...

read more

Dispensing

Boxing System

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...

read more

Transposing Prescriptions

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 written in a plus cylinder form it must be transposed before processing. Transpose a...

read more

The Dangers of Night Driving Glasses

It is an all too common misconception that yellow tinted or yellow polarized night driving glasses are beneficial for night time driving. The thought is, the yellow or amber color reduces glare and improves contrast. However, in reality, when driving at night or dusk...

read more

Harry A. Saake’s 44 Tips for Dispensing Opticians

1. If you have a high plus lens, stay away from long narrow frames as they will tend to pop out of those frames the easiest since they are long across the top. One must understand that one of the reasons for having trouble keeping lenses in a metal frame is the...

read more

Finishing

Remove Scratches from 1.60 and 1.66 Product

Strange but True: You can easily remove most scratches from 1.60 and 1.66 product with a bowl of water and a microwave. Here's how: 1. Place scratched lens(es) in a bowl of water. Use enough water to ensure the lenses remain covered during the heating period....

read more

Flawlessly Edging Super-Hydrophobic Lenses

In just minutes a day, you too can edge super-hydrophobic lenses flawlessly! Editors note: If you are working with our own ICE, UVARity, TKO Plus, or TKO Ultra, you need not read any further, since each comes with a powder coat that virtually eliminates slippage...

read more

Lens Form and Theory

The Electromagnetic Spectrum

Produced by the nuclear cauldrons of stars and all matter in the cosmos, energy in the form of electromagnetic radiation permeates our entire universe. Every second of every day we are bombarded with and surrounded by electromagnetic radiation; some bounces off of our...

read more

Lens Power

As light rays pass through a lens with power, the rays are bent or refracted. In a lens with a plus power, the light rays converge or are refracted toward one another. The point at which the light rays converge is called the focal point and in a plus lens, is behind...

read more

Lens Form: Sphere, Cylinder, and Axis

It can be helpful to think of very basic lens forms in terms of prisms. Recall, as light passes through a prism it is refracted toward the prism base. Minus lenses therefore resemble two prisms apex to apex spreading light rays outward as they pass through the lens,...

read more

Prism

Prism can be used to correct vision for an individual whose eyes are not perfectly aligned as with, for example, a patient with strabismus. When the eyes are not aligned, the right and left eye see different images resulting in blurred or double vision. Sometimes the...

read more

Prism by Decentration

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...

read more

Aspheric Lenses

Aspheric lenses are defined as lenses that are non-spherical. This non spherical surface encompasses all kinds of lenses from aspheric, atoric, progressive, and aphakic. So if all these lenses fall in the definition of an aspheric lens, how do we further define and...

read more

Principles of Atoric Lens Design

Industry studies have shown that approximately 70% of all spectacle wearers receive a cylinder correction for astigmatism. Further, 50% of these wearers have corrections with over 0.50 D of cylinder power. This article will show that conventional lens design does not...

read more

Fundamentals of Progressive Lenses

A progressive addition lens (PAL) is a type of multifocal lens that employs a surface with a continuously smooth increase in addition (Plus) power. The curvature of the surface increases from its minimum value in the distance zone to its maximum value in the near zone...

read more

Resultant Prism Chart

Download the printable resultant prism chart, handy for converting the two-component prescriber's method of specifying prism to a single component resultant method. Resultant Prism Chart

read more

Lens Options and Materials

Lens Materials

Refractive Index The refractive index of a lens material indicates how much the material will refract or bend light as it enters the material from air, by comparing the speed of light in a given material to the speed of light in air. The higher the index number of a...

read more

Video: Lens Material Drop Tests

The following videos show the results of drop tests perfomed by Younger Optics on CR-39, Spectralite, 1.60, Polycarbonate, and Trivex. All tests were perfomed using a 500g missile with a 1 mm point. The lenses tested were all front-side coated with a center thickness...

read more

Basic Lens Styles

Single Vision Single vision lenses, as the name suggests, correct a single refractive error with a single focal length. When a myopic or hyperopic refractive error exists, spectacles are required to correct vision. Minus powered single vision lenses are used to...

read more

Trivex vs. Polycarbonate

Even though Trivex has been available for a while now, there is still much debate and confusion about how Trivex and polycarbonate stack up against one another. We'll lay out the facts and attempt to put the question to rest. Polycarbonate Born from the space race in...

read more

Focus on Progressive Lenses

It Doesn't Last Forever Eventually it gets everyone. That point in a patient's life comes when no matter how perfect their vision may have been as a young adult, they begin to notice changes. The newspaper becomes more difficult to focus or the fine print on...

read more

Focus on Coatings

Lens Coatings - Advancing the Utility of Spectacle Lenses All optical materials, no matter how advanced or well-suited for a patient's needs, suffer from innate shortcomings specific to the lenses chemical makeup. Where crown glass is unquestionably superior in...

read more

Principles of AR Coatings

How Do AR (Anti-reflective) Coatings Work? The Problem: No Time for Reflection As light passes through a lens from air, it experiences a change in index of refraction. When that occurs, some of the incident light is transmitted through the lens medium and refracted...

read more

Polarized Lenses

Far More than Eliminating Glare Photographers often use polarized lenses on their cameras to obtain bolder colors and deeper contrast in their photos. In the same way polarized lenses remove the glare and improve the visual quality of a photograph, polarized...

read more

Polarized Colors, Efficiency, and Use

Polarized Colors, Efficiency, and Use - Color Polarizing Efficiency Trans-mission Use Gray C 98% 25% Reduces the maximum amount of visible light and allows for true color recognition. Good for bright sunny days and heavy glare situations. Best uses include driving,...

read more

The Problem with UV 400 Treatments

Have you ever had the chance and check a pair of lenses that were treated with a UV solution some three to six month after the were made and handed to the patient? There is a good chance, that you will have a big surprise, your UV Meter ( if the instrument measures at...

read more

Photochromic Lenses

Photochromic is a generic term to define a lens with a characteristic of changing state from clear to sunglass dark when exposed to light. Over the years this option has been available in many different chemical, material, and color combinations; as well as offered by...

read more

Low Vision

Low Vision Care: An Overview

Low vision patients are the most under-treated, under-referred and generally overlooked patients in many eyecare practices. With the current growth in the elderly population, this may be a perfect time to re-evaluate your approach to this ever-expanding group of...

read more

Take a Second Look at Low Vision Care

Aging boomers mean that low vision services can be lucrative for your practice. In the United States, vision loss that can't be corrected with glasses, contact lenses or surgery is the third most common ailment affecting individuals over 65 years of age (exceeded only...

read more

Ocular Anatomy

Video: Histology of the Eye

An outstanding overview of the major structures of the eye from the University of Missouri Medical School including: the Cornea, Lens, Ciliary Body, Iris, Ciliary Epithelium, Canal of Schlemm, Neuron Chain, Rods and Cones, Neural retina, and Fovea...

read more

Extraocular Muscles

Extraocular Muscles The stabilization of eye movement is accomplished by six extraocular muscles attached to the eye via the sclera. The six muscles and their function are: Lateral rectus - moves the eye outward, away from the nose Medial rectus - moves the eye...

read more

Refractive Errors

Refractive errors occur when abnormalities of the eye prevent the proper focus of light on the retina. Emmetropia refers to an eye free of refractive errors. Common Refractive Errors Two common types of refractive errors are myopia and hyperopia. Myopia Myopia, also...

read more

Common Eye Disorders

Amblyopia - a reduction or dimming of vision in an eye that appears to be normal. Also commonly known as lazy eye, amblyopia is an eye condition noted by reduced vision not correctable by glasses or contact lenses and is not due to any eye disease. The brain does not...

read more

Major Ocular Structures

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 for nourishment, called the vascular tunic, which consists of the iris, the choroid, and the...

read more

Refracting

Basic Refraction Procedures for Opticians

Many opticians around the country have shown great interest in learning the procedures involved but have been unable to take a course on the subject. This article is designed to introduce the subject to those interested, and to provide some continuing education to...

read more

Surfacing

Understanding Prism Thinning

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...

read more

Methods for Estimating Lens Thickness

Often, it is beneficial for the eye care professional to predict the finished thickness of a pair of spectacle lenses. Determining the change in thickness that results from the patient's use of a different frame or lens style is a common example.Patients investing a...

read more

Don't Miss Out!

Join Over 10,000 Other Optical Professionals. Become the best optician you can be with weekly content; tips, stories, and science to help you focus on getting the most from your optical business and career delivered to your inbox.

You have Successfully Subscribed!