|Oakley uses ballistic testing to ensure impact resistance in its sunwear.|
ECPs need to know the performance levels available in sunwear to relate to patients’ needs.
Have you ever wondered just how tough the sunglasses you offer your patients are? Here are some insights you’ll find helpful.
There are several voluntary standards that sunglass manufacturers follow. Virtually all sunwear makers choose to follow optical industry standards established by the American National Standards Institute (ANSI), which produces over 20 standards that apply to assorted ophthalmic areas. If you’re selling sunwear, you’ll want to know the standards the product is claimed to meet so be sure to ask.
SPECIFIC TO SUNWEAR
It may surprise you that there is only one standard specifically for sunwear: ANSI Z80.3-2010, produced by the Z80 Ophthalmic Committee for ANSI—this sunwear standard is titled “Non-prescription Sunglass and Fashion Eyewear Requirements.”
The Z80.3 standard applies to plano sunwear that is mass produced. In other words, it was created for sunwear that will be made by hundreds or thousands in a mass production environment and is not intended for prescription eyewear use. Even so, Z80.3 covers everything from the sunglasses at the gas station checkout counter to higher-end products found at the sunwear shop at the local mall.
Requirements in the Z80.3 standard include light transmission, traffic signal color recognition, power tolerances (even though they are plano), cosmetic quality, flammability, and resistance to radiation, among others.
The requirement for lens strength or safety is the FDA required lens impact-resistance test commonly known as the drop-ball test. This is the same test found in the Z80.1 standard that governs dresswear ophthalmic prescription eyeglasses and is the most severe impact requirement of any nation. The test consists of a 5/8-in. steel ball, weighing 0.56 oz. being dropped on the lens from a height of 50 in. Imagine a marble being dropped from the height of light switch on the wall and you’ll get the idea. There is no test for frame strength, safety, or durability under Z80.3.
Let’s say your patient takes your recommendation and wants to buy a pair of plano sunglasses to wear over her contact lenses. Since you don’t stock plano sunwear, you help her chose an ophthalmic frame and recommend some gray 80% for it. Since these are plano, they fall under the Z80.3 standard, right? Nope! Because they are considered custom made, her sunglasses fall under the Z80.1 standard known as “Prescription Spectacle Lenses.”
This is the standard you’re probably familiar with because it covers the lenses you fabricate and sell in your office everyday. It is the standard used to judge all ophthalmic lens work that does not fall under Z80.3 or Z87.1 (the safety eyewear standard).
Like Z80.3, Z80.1 also covers a wide range of topics including but not limited to: tolerances for power, tolerance for base curve, prism imbalance, physical appearance, and segment placement. The only topic that applies to the strength or safety of eyeglass lenses is the same Impact Resistance Test specified in the sunwear standard Z80.3. It’s important to know that in the drop-ball test the lens alone is placed on the end of a rigid tube while it is struck. The Z87.1-2010 industrial safety eyewear tests are performed with the lenses mounted in the frame and this is mounted on a head form.
Z80.5 covers frames used in the production of prescription eyeglasses. This includes topics such as angles, temple types, measurements, markings, materials, and more. The topic that applies to the strength of a frame is “lens retention,” which states the frame must not allow a lens to be dislodged by a frontal blow of a 5/8-in. steel ball dropped from a height
|Wiley X Climate Control Series is ANSI Z87.1 certified.|
of 50 in., the same test parameters used to test lens impact resistance under Z80.1 and Z80.3.
Frames made to the Z80.5 standard are suitable for mounting sun lenses because they have a standard V-groove to accept an edged lens. Plano-power sunglasses can be a very different story because in most cases they are not designed to accept conventionally edged lenses. The result can be unacceptable lens retention in the frame. Always confirm with your supplier that sunglass frames are ready for mounting prescription lenses.
The Z80.1 standard for prescription eyeglasses explicitly states that it, “…may not be applied to Personal Protective Eyewear,” which is covered by Z87.1, or “Players of Selected Sports,” which are covered by ANSI/ ASTM F803. Some sunwear companies manufacture some or all of their products to the same level of impact protection that safety eyewear is held to. The standard that defines this level of protection is known as the Z87.1, the American National Standard for Occupational and Educational Personal Eye and Face Protection Devices. The Z87.1 document specifies tests for safety lenses, frames, and complete devices. Sunwear that meets this safety standard is substantially more impact resistant than dress sunwear.
The Z87.1 standard covers many topics including tolerance for powers, minimum thickness, markings, light transmission, ignition, corrosion, and impact resistance, among others. Many of the tests are conducted with a complete pair of glasses mounted on a headform to simulate real wearing conditions. This helps assure wearers receive the benefits manufacturers are attempting to build into their products.
There are four impact tests in this standard. In the lowest level test, a 1-in. steel ball dropped onto the lens from a height of 50 in. is required of all Z87.1 eyewear. The impact is like that of missing a golf ball thrown to you from just a few feet away and having it hit your eye. This does not, however, qualify the eyeglasses for use where there may be an impact hazard. In order for Z87.1 eyewear to be impact rated it must pass three additional, more severe tests. High-mass impact testing uses a steel missile weighing 17.6 oz. dropped from a 50-in. height. This impact is similar to getting hit in the eye with the end of a shovel handle.
High-velocity impact testing fires a 0.25-in. steel ball weighing 0.037 oz. at 150 ft. per second (about 100 mph) at the lens. Think of this as being shot in the eye with a BB gun. The penetration test drops a “needle” weighing 1.56 oz. from 50 in. away. This is like a dart tossed at your eye. As you might suspect, lens retention is also an important factor in safe sunwear, and this standard describes lens retention requirements.
What does all this tell you about buying and selling sunwear? It proves you need to be asking lifestyle questions to your patients and really listen to what they tell you. Will their sunwear ever leave the poolside? Are they playing sports in them? Are they wearing them on a job site? Do they hunt or shoot while wearing them? Are they grinding, cutting, and hammering at home? The more you know about their needs and your products’ testing, the better you’ll be able to recommend the right sunwear.
John Seegers is a licensed optician at Ryan Vision Center in Henrico, VA, and the creator of opticianworks.com.