The importance of quality eyeware was publicly manifested by the Navy Air Corps in 1951 when it commissioned Bausch and Lomb to begin developing a high-quality sunglass lens that would be suitable for prescription use. To that point, sunglasses were little more than darkened plates of untempered glass. The result of the Navys action was the invention of B & Ls G-15 glass, which received great public acceptance that it was introduced as Ray Ban sunglasses in 1953.
The industry has since blossomed: It now markets more than 200 million units every year, with gross sales of $3 billion, industry experts say.
Beyond that, the Food and Drug Administration now says that sunglasses are a medical device and fall within the realm of government scrutiny. Most physicians agree that a lack of proper eye protection may lead to serious medical problems and an acceleration of the aging process.
The medical issues involved are as serious as those involved in cancer-related problems associated with the failure to use sunscreen. The same Ultraviolet light rays, identified as UV-A, UV-B, and UV-C, that contribute to skin cancer, pass directly through the eyes outer layer and may have harmful, long term effects.
Continued exposure to UV-A, for example, may cause the formation of cataracts on the lens of the eye. The result is permanent clouding of the lens that is impenetrable by light, with a corresponding loss of vision.
UV-B rays inflame the outer layer of the eye and may result in keratitis, commonly referred to as snow blindness. Though this is usually a temporary condition from which eyes recover with rest, people who encounter the problem are more susceptible to problems in the future.
UV-C is the most dangerous but is, fortunately, almost entirely absorbed by the ozone layer.
A fourth hazard is the exposure to infrared (IR) light, heat radiating from the sun that has the greatest effect on wearers of soft contact lenses. The most telling effect of IR is fatigue and dryness of the eyes, so experts recommend that less than 25% of the IR in the environment should reach the eyes. They also tell us that glass is better at preventing IR from reaching the eye than plastic.
Throughout much of the United States, exposure to wind, dust and snow may lead to a condition known as pterygium, a growth of cells between the eyelids and the cornea requiring surgical removal.
Theres also a carry-over affect from the lack of proper eyewear: Night vision, which is critical to many sailors, is enhanced by the use of sunglasses, as well. Eyes that may require up to three hours to overcome extended exposure to direct sunlight will require half that time to adjust when properly shielded.
In an effort to create a measuring stick, the American National Standards Institute (ANSI), in conjunction with industry organizations and manufacturers, has developed an agreed-upon set of standards related to safety and performance issues for evaluating sunglasses.
Lenses now fall into three categories, and should be clearly identified on packaging. Cosmetic lenses may absorb as little as 70% of UV-B and 20% of UV-A rays, and should be avoided entirely; general purpose lenses absorb at least 95% of UB-V and 60% of UV-A, but are not recommended for use in highly reflective environments.
Special purpose lenses, which are the most appropriate for sailors, absorb 99% of UV-A and 60% of UV-B.
But there are a couple of hitches. Because the industry is essentially self-policing and the types of glasses sold on racks in convenience store are mass produced in foreign countries under no regulatory supervision, eyeglasses with 100% UV Protection stickers may not be accurate. Second, theres no standard place on the face to measure the UV; some measurements are made directly in front of the lens, which ignores rays that may bend around the frame to the eye.
As a consequence, we tested glasses that most effectively prevent rays from reaching the eyes, primarily products with wraparound frames.
For all practical purposes, lenses come in two flavors: glass and plastic, of which there are several types-acrylic, polycarbonate, and CR-39.
Theres no arguing the fact that optically ground glass lenses provide the highest level of visual acuity and optical quality, which is why its used in high-quality cameras and telescopes. In addition to being more scratch-resistant than plastics, modern glass sport lenses are now available in tints that will not distort color. The major drawbacks to glass have historically been the fact that it is heavier than plastic, and is not shatterproof.
The weight problem has been ameliorated by the introduction of borasilicate, which is nearly as light as plastic, but does not impair visual quality. Many glass lenses meet ANSI standards for impact resistance, a test administered by dropping a steel ball onto a lens from a height of 50″. By comparison, polycarbonate has been demonstrated to deflect a .22 caliber bullet fired from 50′, and is considered superior on that count.
Optical polycarbonate is considered the toughest and most impact-resistant product on the market, and is offered by most major manufacturers along with their glass products. It is, however, susceptible to scratching, especially by salt crystals.
CR-39, which was developed during World War II by Pittsburgh Plate Glass, is superior to polycarbonate because of its optical qualities, and the fact that it has similar impact resistance and is the most scratch-resistant of plastic lenses.
Finally, theres the issue of light transmission. Experts generally agree that a pair of sunglasses should eliminate 85% of the available light, which they describe as having a 15% light transmission factor. The best products for sailors have a light transmission factor of 15%-30%.
Tinting and Mirrors
Because we live in a multi-colored world of red and green buoys, blue and overcast skies, haze and fog, and LCD instruments, selecting a lens that does not distort colors is important. Opticians say that our eyes see varying shades of blue, green and yellow in the color spectrum, but are disturbed by tinting that reduces the ability to discern the difference between blue, red, green and black.
Neutral gray provides nearly uniform absorption of all colors in the spectrum, and offers the truest color fidelity. Rose tints enhance contrast and reduce glare in hazy and bright conditions; the Sunclouds we tested made the sky bluer and some reds more intense without affecting our ability to discern color.
Amber and brown tints filter a large percentage of blue light, which help improve contrast and sharpen details. Because they reportedly are ideal for low-light situations encountered in haze and fog, we tested a pair in the rain and found they improved our vision. Similarly, a copper tint will enhance contrast in hazy light while maintaining good color fidelity. We also found that moving from amber to yellow or orange tints, which eliminate blue light waves, made it difficult to recognize red versus yellow, or blue versus green or black.
Depending upon the manufacturer, youll pay 15%-30% more for polarizing, a rather steep price, but one we think is worth the investment. While the companies won't divulge the specifics of their proprietary processes, we know that polarizing involves the sandwiching of glare-reducing elements between lenses. A polarized lens makes it possible to see below the waters surface in certain conditions, and to more easily see wind and wave patterns. More important, we think, is the reduction in squinting, which results in eye fatigue and headaches.
Mirrored lenses, like Sunclouds, employ a reflective coating on the lens surface to deflect glare, and may also apply polarizing to the same lens. The affect of the mirroring is to deflect overhead light and light deflected upward from the surface. We think this is an excellent combination.
We evaluated more than 30 samples provided by 12 manufacturers, some of which were included in our 1994 study. However, we eliminated the low-cost, poor-quality glasses, including acrylics and goggle types that fit over regular glasses. Though they may block the suns rays, their optical qualities are so poor as to cause distortion and the potential for headaches.
Our primary concerns were the quality of the lens, distortion, color, tinting, effect of polarizing, comfort of frames, amount of light actually reaching the eyes from the front or sides, reflection from the back, and price. We tested all the sunglasses in all types of conditons: on the water on gray and bright days, in both rain on snow, and in an open space on a sunny day.
Although we tested glasses enclosed in traditional styles of frames like the aviator frame, we found that the space between the eyeball and lens was great enough to allow direct or reflected light to reach the eye. In our opinion, a frame that fits the contour of the owners head and provides protection from the side is important. When auditioning frames, check for clearance between the lens and your eyelashes. On the other hand, some users will prefer aviator-style frames that hook over the ears and won’t go into the drink. Others should consider Croakies or similar means of restraint.
In the eyewear industry, wed consider Bausch & Lomb to be the proverbial 10-ton gorilla, since it owns Ray Ban, Revo, Suncloud, Killer Loop, and Porsche eyewear. With that diverse product line it produces lenses and frames in a wide assortment of materials, and with prices ranging from $89 (Suncloud 1-70) to $295 (Revo Sport Wrap).
However, we found products from Nikon, Hobie, Vuarnet, Ultrasol, and Oakley that measured up to B & L.
Among those in the mid-price range with glass lenses, we narrowed our choices to the Ray Ban Daddy-O ($149), Hobie Eclipse ($140), Suncloud Moat ($169), Vuarnet PX 3000 ($155), Ultrasol Classic ($130), and Nikon Lightning ($110), all of which cost less without polarizing. All of these products had excellent optics and light transmission, some good enough that we could wear them indoors with little noticeable loss of vision. Both the Hobie and Nikon lenses are borasilicate, so are a bit lighter, which may make a difference if a prescription is necessary.
All had frames that wrap comfortably around the head, and the polarized lens cut glare dramatically. The Ray Ban, Nikon and Suncloud lenses also have an anti-reflective coating on the inside, which reduces indirect glare, as well. The most noticeable additional characteristic of the Suncloud and Ray Ban was a rosy tint, which we liked, and split mirror lenses that reduce reflection from above and below. We think those are a real plus.
When testing plastic lenses, we added Oakley to the equation.
The consummate marketing company, Oakley has products seen on the heads of Whitbread racers, major league baseball players, Olympic athletes and drivers on the NASCAR circuit. It has also invented its own language: polycarbonate lenses are called Plutonite, coatings are called Iridium, and frames are equipped with patented Unobtainium earsocks to prevent slippage.
We compared Oakleys Straight Jacket ($150) and Frogskin ($115), the new polarized lens with wraparound frames, to Sunclouds Ledge ($89) and I-70 ($89) and Hobies Durango ($115), with a C-39 lens we prefer because its more scratch resistant. As in our last test, wed still rank the Hobie as having best optics, although the Suncloud Ledge also has good optics, an anti-reflective coating, and split mirror coating. All three companies produce gray or amber lenses, so colors are easily distinguishable. Light transmission was only 15% with all three, which is adequate protection from sunlight.
Of the high-priced products, Revo was our best buy in the high-priced ($185, then) category in our August 15, 1994 evaluation, so we compared their newest product, the Revo Sport Wrap ($295), to Nikons Pacifica ($180).
Revos lens technology was adapted from the NASA space program, and introduces a multilayer film coating that is used to enhance and protect lenses of cameras and telescopes from the sun. The pair we tested had a gray lens and excellent optical qualities, and a very light, comfortable frame. The company says its polarizer blocks 95% of reflected glare.
Nikons fine camera lens technology has been employed in its line of sunglasses. The Nikon Pacifica model has a borosilicate glass lens enhanced by an anti-reflective coating on the back of the lens, and gradient mirrors that block light overhead and below. We found the GX lens to be brighter than the Revos, although there was no noticeable difference in clarity.
First, buy quality. If necessary, eliminate the polarized lens in favor of buying good, plain lenses.
Then, if you can’t find the information you need to make a good purchase decision, check with an optician. Youll want to evaluate light transmission levels, and the quality of the lenses. We think glass is better than polycarbonate.
However, where there is the risk of being struck in the face with a hard object, non-shattering poly will be safer. Evaluate several pair of glasses to determine which produce the highest clarity for your eyes.
Then, select frames that enclose as much of the eye as possible, front and side, but make certain they are comfortable; sunglasses are of no use when they are stored in a drawer. Finally, take them outside to see how they perform in real conditions, not in the fluorescent lighting of a retail store.
We think the Nikon Lightning, which combines high-quality optics with a rugged wraparound frame, is a best buy at $110. However, the frame, which fits snugly, may be too small for some people, so our second choice is the Hobie Eclipse, which also offers quality optics with an excellent frame, for just $30 more.
Among the polycarbonates, we liked the Suncloud Ledge for its optics, polarizing and mirrored combination, frame design, and price. However, for another $25, you can get Hobies Durangos, which provide a bit more scratch-resistance and arguably better optics.
For discount prices on the Internet, check out www.pepsun.com/closeout.htm
Contacts- Digi Sportlens, 800/750-3444. Hobie, 800/554-4335. Oakley, 800/733-6255. Nikon, 800/645-6689. Ray Ban, 800/ 472-9226. Revo, 800/843-7386. Suncloud, 800/578-8767. Vuarnet, 800/348-0388. Ultrasol, 310/371-7762.