Educational Content

 

Comprehensive Eye Care

 

All about eyeglass Lenses!

 

  • Introduction
  • Basic Refreactive Errors
  • Bifocals and Progressives
  • Hi-Tech
  • Lens Materials
  • Lens Coatings
  • Tints

Eyeglass Lenses are not a commodity!

This section of our website provides technical information about eyeglass lenses: how they work (Basic Refractive Errors, Bifocals and Progressives), what they are made of (Matrials), and how they can be enhanced (Lens Coatings, Hi-Tech, Tints). Click a tab above to learn more. If you are interested in Contact Lenses or Laser Vision Correction you can explore those subjects, too.

How a Certified Optician can help you

Have you ever been to a store and been unable to find a person knowledgeable or qualified to answer your question? Our Opticians are certified by the American Board of Opticianry. A certified Optician is one who has passed a multi part examination and must further complete continuing education each year to maintain certification. Our staff is very well trained…… Many things go into the cost of a pair of glasses. Frame material, lens technology, and the skill level of the people making the glasses can determine the durability, comfort and cost of the glasses. Craftsmanship and quality control result in better eyeglasses just as in any other highly skilled trade. If you are building a house, you would likely get the best constructed house by using an experienced, licensed contractor who will use quality materials to ensure you get a house that lasts. When you are building a pair of eyeglasses, our experienced, certified Opticians use quality materials to ensure you get the most out of your eyewear.

Historical Note

First invented in the 13th century, and patented in the 18th century, corrective eyeglass lenses are the most common form of optical correction in use today. Bifocals were invented almost certainly by Benjamin Franklin in the 18th century. Correction for astigmatism was a 19th century discovery. If you're a history, art or antiques buff, you must visit Dr. David Fleishman's antique spectacles website.

 

 

 

Conditions correctible with Eyeglasses

A contact lens is designed to improve vision. Contact lenses can correct eye conditions including myopia, hyperopia, astigmatism, and presbyopia.

Myopia (nearsightedness)

A vision condition in which objects at near is clearer than objects that are far.

Hyperopia (farsightedness)

A vision condition in which objects that are far are clearer than objects that are near.

Astigmatism

Blurry vision caused by an irregular shape of the cornea or sometimes the curvature of the lens in the eye.

Presbyopia

The loss of the eyes’ ability to focus at near due to loss of elasticity of the crystalline lens. It usually occurs around age 45.

Presbyopia

literally means 'Old eyes' and reflects the loss of ability to focus on objects at near distances. To be able to wear eyeglasses without the need to take them on and off, presbyopes need at least two different corrections, one for distance viewing and one for near viewing. A major advance in eyeglass lenses came in the 19th century with the invention of the bifocal lens to aid presbyopic wearers.

Bifocal and Trifocal lenses

Since the invention of lined bifocals, the method of manufacture, size and location of the segments, and number of segments have been modified to create today’s designs. One of the most distracting problems for wearers of bifocals is the visible line dividing the near and distance sections. Another issue is the inconvenience of “image jump” when switching between the near and distance sections of the bifocal lens.

Progressive Lenses

These are very attractive lenses. Designed to overcome the problems of bifocals, the current state-of-the-art in multifocal lenses is the progressive addition lens (PAL). PALs have no visible lines, as there are no discontinuities in power on the surface of the lens. Progressive lenses are the closest eyeglasss can bring you to how natural vision is prior to the onset of prebyopia. Progressive lenses provide a smooth transition from distance through intermediate to near. With this constant graduation you can look up to see in the distance, look down to read and look straight ahead to see things such as your computer screen.

Progressives for Computer

While the "general purpose" progressive lens works well for most activities, people who use a desktop computer for more than 2 hours a day do better with a special type of progressive we could call "office" or "computer" glasses. These lenses generally devote the forward vision to computer distance, while reserving a generous lower area for reading material held at normal reading distance (a bit closer than the computer monitor).

Today, approximately 38% of all multi-focal lenses sold in the U.S. are progressive. Even so, the principles behind progressive addition lenses still remain somewhat of a mystery to many. Conventional progressive addition lenses are onepiece lenses that vary gradually in surface curvature from a minimum value in the upper, distance portion, to a maximum value in the lower, near portion. The result is a smooth, continuous increase in surface power that provides the necessary near addition (or add power), without any visible lines of demarcation or abrupt disturbances of vision. A typical, general-purpose progressive lens will have three distinct zones of vision: 1. Distance. A designated zone located in the upper portion of the lens, which provides the necessary distance correction. 2. Near. A designated zone in the lower portion of the lens, which provides the required near addition or add power. 3. Intermediate. A ‘corridor’ in the central portion of the lens connects these two zones, which increases progressively in plus power from the distance to near. These three zones of vision blend together seamlessly, providing the wearer with a continuous depth of field from near to far, as illustrated below. The benefits afforded by the optical features of a progressive addition lens include: • No visible segments or lines of demarcation— provides more cosmetically appealing lenses with continuous vision, free from visually distracting borders; • Clear vision at all distances—provides vision that more closely resembles the lost accommodation of the eyes; and • No unwanted image displacement—or jump—ensures that there are no abrupt disturbances of vision.

 

 

The Future:

Atoric Lenses: Atoric lenses continue to be a growing portion of new ophthalmic lens products. These lenses combine two aspheric curvatures on the same surface, making them ideal for those patients with astigmatism. Just like aspheric lenses lead the way for improvements over spherical base curve designs, atoric lenses are leading the way for improvements with cylinder prescriptions. It is likely that the majority of cylinder lenses will have an atoric design in the not very distant future.

 

Eyeglass Lens Materials

 

Plastic:

For the last decade more lenses in plastic have been made instead of glass. Plastic lenses are more comfortable and light. There are different types of lens materials. Depending on how strong your prescription is, the doctor may recommend high index lenses. These lenses are flatter and lighter.

Special Materials for stronger corrections

 

High Index Lenses:

Recent advances in lens material technology have made lenses available with characteristics that were only dreamed of just a few short years ago. Advantages of High Index Lenses Thinner: New lens materials bend light rays more than old-fashioned plastic lenses. Your lenses are up to 35% thinner. Lighter: Lower specific gravity means lighter lenses. Thinner lenses are also lighter, by as much as 43%.

Aspheric Lenses:

Added Advantages: Complex mathematics and sophisticated manufacturing techniques help create a lens surface designed to eliminate most front surface bulging and the distortions at the lens’ edge inherent in old-fashioned plastic lenses. Slimmer Profile: The use of flatter curvatures creates a slimmer lens profile: lenses don’t bulge out of your frame. Better Peripheral Vision: Vision through the lens is clear, right to its edge. More Natural Appearance: Less distortion means you will see the world more clearly and, equally as important, you’ll look more natural to those looking at you. III. ASPHERIC LENSES Aspheric Lenses In an aspheric design, the lenses have flatter curves; this means lenses do not "bulge" out of the frame as much as regular lenses. The side profile of aspheric lenses is, therefore, slimmer, which greatly enhances the appearance of finished eyewear. Unlike hi-index lenses, aspherics provide substantial benefits for both nearsighted and farsighted wearers. Benefits of Aspheric Lenses Superior Optics: A basic principle of optics dictates that distortion is created when wearers look away from the center of a conventional lens. Aspheric lens designs reduce or eliminate such distortions. This is because, as the eye travels away from the center of the lens, the front curve changes, keeping the optics crisp and clear. This s is why all expensive camera lenses feature aspheric curves. More Natural Looking: Strong farsighted lenses have a tendency to enlarge the wearer's eyes, producing an unattractive magnified look. Strong nearsighted lenses do just the opposite: they minimize the wearer's eyes so they tend to look small and beady. Because they are flatter, aspheric lenses fit closer to the eyes thereby lessening this magnification or minimization, for a more attractive, natural look.

Frame Selection:

For several reasons, frame selection is important with aspheric lenses. In general, the best looking eyewear results when the frame is not overly large and when the eyes are centered in the middle of the frame opening. Taking measurements for aspheric lenses requires greater care and skill on the part of the optician. Creating the complicated curves used in aspheric lenses makes them a little more expensive than conventional lenses. But the outstanding cosmetic and visual benefits of these marvelous lenses make them a good investment. Reflections: Since aspheric lenses are flatter and positioned slightly closer to the face than conventional lenses, some wearers may notice more reflections off the flatter back surface of the lenses. The best way to eliminate these reflections is to order an antireflective coating, which also improves vision through the lenses.

To Whom Do We Recommend Aspheric Lenses? We recommend aspheric lenses to patients with a prescription greater than 3.00 Diopters, either of myopia (-3.00) or hyperopia (+3.00)

 

Coatings that improve vision and durability

There are a variety of lens treatments that may benefit your vision. Anti Reflective Coating (ARC) increases the transparency of the lens and may be beneficial for computer use and reducing glare when driving at night. Scratch-Resistant Coating (SRC) Although this treatment does not totally eliminate scratches, it does increase the longevity of the lens and prevents small scratches.

Anti-Reflective Coating:

Anti-reflective coating is an incredibly thin, multi-layer coating that virtually eliminates lens reflections. Advantages of Anti-Reflective Coating More Natural: Less glare and reflection means you will see the world more clearly and, equally as important, you’ll look more natural to those looking at you. Increased Vision: Anti-reflective lenses diminish glare, reflections and ghost imaging, thereby helping you see better. Clearer: By allowing more available light to filter through your glasses anti-reflective lenses help you see things more clearly.

Scratch and Wear Resistant:

Advances in technology from only a few short years ago make anti-reflective coatings both scratch resistant and wear resistant. Unconditional Warranty: Our best anti-reflective coating comes with a two-year unconditional warranty.

There are a variety of lens treatments that may benefit your vision. Anti Reflective Coating: or ARC increases the transparency of the lens and may be beneficial for computer use and reducing glare when driving at night. Scratch-Resistant Coating: Although this treatment does not prevent scratches, it does increase the longevity of the lens and prevents small scratches.

Transitions:

These lenses changes color with UV light. Outside they get dark and indoors they clear up.

Tinted Lenses

With over 500 available options, tinted lenses are one of today’s most popular eyewear features. Lens tints range from neutral to fashion colors and can help you look and see better in a variety of settings.

Picking the Right Tint for Sunglasses

Neutral Tints: Gray or gray-green lenses provide the most comfort and long-term wearability of all tints. They are excellent for general purpose use because they allow even transmission of all colors of the spectrum, which provides more natural vision. In addition, gray lenses are suggested for water sports.

Contrast Enhancing Tints: Contrast Enhancing, also known as performance tints, are recom­mended for sports and activities that require the ability to see detail and contrast. Depending on the shade, they reduce varying degrees of blue light from the spectrum. Blue light, which is a scattering, shorter light wave, falls in front of the eye's focal point, reducing visual acuity. Without a blue light blocker, viewed objects will lose their clarity. Contrast-enhancing tints range from browns and coppers, which remove some blue light, to yellows or oranges that block all of it. Day Driv­ing Lenses: Brown and copper, transmit the right balance of blue light to allow for increased contrast enhance­ment while permitting true color values need­ed to differentiate traffic lights. Browns are also recommended for golfers who need to distinguish a white ball in a sea of green. Enhanced Depth Per­ception: SkeetersYellow and amber eliminate all blue light and are recommended for precision sports such as archery or clay pigeon shooting. They are also suggested for early morning or late afternoon light condi­tions and for low-light conditions such as haze, fog, or overcast days because they improve per­ception and brighten the environment. Cyclists, golfers, and skiers also will benefit from this tint.

Fashion Tints: Fashion tints are cosmetic in nature. They are the perfect solution if you want softer-looking eyewear to help camouflage the signs of aging. Our opticians have turned these lens-tinting techniques into makeover magic. Please ask to see the tint samples and for a demonstration.

Club Tints: Club tints, like fashion itself, change all the time. Today’s most popular colors include lavender, light blue, and pink. They make wearing eyewear fun and fashionable.

Cosmetic Tinting and Color Analysis

Cosmetic Tinting & Color Analysis: Here are some creative ways to tint lenses that enhance facial features and even help minimize signs of aging. Types of Cosmetic Tints:

Solid: The entire lens surface is the same color. Available in a wide range of colors and shades

Gradient: Is darker at the top and becomes gradually lighter, until clear at the bottom. Also available in a wide range of colors and shades.

Mirror: A two-way mirror coating is applied to the lens surface. Mirrors provide superior sunlight protection and cosmetic effect.

Other Uses of Cosmetic Tinting

Besides reducing glare, cosmetic tinting offers a wide variety of ways to enhance the appearance of your new eyewear and your appearance. Here are a few:

Mini-face lift: Treat yourself to a mini face-lift, by tinting your new lenses slightly darker at the 10:00 position on the right lens and the 1:00 position on the left lens. It works like eye shadow to accent eyes.

Cheek blush: Tinting the bottom of your new lenses with a rose or peach tint will give your cheeks a bit of color, much like blush makeup.

Minimizing wrinkles: Use a peach or beige cosmetic tint, if you have warm skin undertones, to minimize lines and bags around the eyes. Use a light gray cosmetic tint if you have cool or olive skin undertones.

To enhance eye color: For blue eyes, try a blue gradient lens tint; for green eyes, use green gradient and etc. This will accent your eye color and detract from aging lines. Instant tan: If you have a warm complexion, gradient tinted lenses in orange-sand topped with a gradient flash mirror coating will kick up golden tones in your skin for a sun-kissed look.