A Guide to Sunglasses as Safety Gear

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Unless you’re exceptionally light sensitive, you probably regard sunglasses as an accessory to your outfit or a convenience that you can live without if you forget them when you leave the house. The truth is that sunglasses are an important piece of protective gear that every person should wear. Recent studies have shown that incidents of cataracts, glaucoma, macular degeneration, and a slew of other eye conditions are on the rise and the average age of those affected is decreasing. Optometrists recommend that everyone wear sunglasses, even on cloudy days, because just like our skin, our eyes can get sunburned and that can lead to long-term damage and a greater chance of eye problems when we’re older.

In addition to the average person knocking around town on a sunny day, sunglasses are essential for drivers, hunters, hikers, military personnel, and law enforcement. For these men and women, eyewear becomes critical safety gear protecting their eyes in ways that go far beyond potential damage from the sun. In this article, we’ll look at the potential hazards to our eyes and the ways sunglasses can protect us.

Radiation Protection

"Radiation is one of the primary hazards to our eyesight and probably the least understood."

Radiation is one of the primary hazards to our eyesight and probably the least understood. Even the worst infomercials or cheapest convenience-store sunglasses tout “100% UVA and UVB protection,” but what does that even mean? The dictionary definition of radiation is:

a. the process in which energy is emitted as particles or waves;

b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and absorbed by another body.

The key part of this definition, as far as your eyes are concerned, is those last four words: “absorbed by another body.” When the sun emits radiation, unprotected eyes absorb it and that’s when damage can occur. Our eyes are particularly sensitive to radiation, and the cells in the eye don’t get replaced nearly as fast as our skin cells do, so damage from solar radiation has long-lasting effects.

 


Optometrists recommend that everyone wear sunglasses, even on cloudy days.

Just as we (should) put sun block on when we’re outside to avoid sunburn, we (should) protect our eyes when we’re outside, for the same reason. Since we can’t slather lotion on our eyeballs, the next best thing is to wear sunglasses that block the most damaging radiation—ultraviolet. Let’s take a look at the different types of UV radiation and what kind of damage they can inflict upon our eyes.

As the name implies, ultraviolet (UV) radiation exhibits frequencies greater than violet light, the highest frequency visible to humans. UV radiation is separated into three types: A, B, and C.

UVA: Humans require this light to synthesize vitamin D. However, too much of a good thing can be bad for you. UVA radiation is closer to our visible spectrum and is lower in energy than UVB and UVC rays. It is able to pass through the cornea, reach the lens and retina inside of the eye, and has been linked to cataracts and possibly macular degeneration.

UVB: This class of light is what is responsible for suntans, sunburns, and an increased risk of skin cancer and wrinkles. In a perfect world, UVB rays get filtered by the ozone layer, but with its ongoing deterioration, an increasing amount now reaches the earth's surface.

UVC: The good news is that while this is the most powerful, and thus potentially most damaging of the UV spectrum, virtually all of it is filtered by the ozone layer. The bad news is that the ozone layer is thinning, so there is an increasing risk of UVC eventually penetrating to the surface, accompanied by a slew of serious health risks.

The US Environmental Protection Agency (EPA) maintains an excellent sun safety section on its website that does a great job of explaining the UV Index. Even for the lowest rating of 0, the EPA still recommends that sunglasses be worn.

High-Energy Visible Radiation

Even with lower energy and longer wavelengths than UV rays, High-Energy Visible (HEV) light, sometimes referred to as “blue light” due to the bluish tint it casts on things, has the ability to penetrate deep into the eye and cause retinal damage, as well as macular degeneration.

Eye Conditions

Just as radiation is largely misunderstood, so are the diseases and conditions caused by it. Here is a brief explanation of the most common negative effects of radiation on our eyes:

Cataracts: A buildup of protein in the lens causes it to lose its transparency and become cloudy, obstructing vision. If left untreated, cataracts can lead to blindness. Although curable with modern eye surgery, cataracts diminish the eyesight of millions of Americans and cost billions of dollars in medical care each year.

Pterygium: A growth of fleshy tissue on the white of the eye. It typically forms on the side closest to the nose and grows toward the center of the eye. Extreme cases may affect vision, but normal occurrences result in the feeling of a foreign object in the eye (like dirt or an eyelash), burning, itching, and intermittent blurry vision.

Pinguecula: Often a precursor to Pterygium, this is a yellowish patch or bump on the conjunctiva near the cornea. A common effect of Pinguecula is that it can block tears from keeping the eye moist; it will cause excessive dryness and the feeling of having a foreign object in the eye.

Macular degeneration: The degeneration of the part of the retina where visual perception is most acute, it results in a loss of vision in the center of the visual field, making it difficult or impossible to read or to recognize faces. Typically a person suffering from MD will keep their peripheral vision.

Glaucoma: A condition where pressure inside the eye builds up and damages the optic nerve. The optic nerve is responsible for transmitting images to the brain, and the increased pressure on the nerve will cause reduced eyesight and eventually total and permanent vision loss.

Skin cancer: This is the most common type of cancer afflicting humans right now. About 1 million people are diagnosed every year in the US alone.

Protection

"To protect your eyes from the damages of UV and HEV radiation, you’ll want to get a pair of sunglasses that offers 100% UVA and UVB protection."

To protect your eyes from the damages of UV and HEV radiation, you’ll want to get a pair of sunglasses that offers 100% UVA and UVB protection. If you’re working outside—such as house painting, landscaping, or lifeguarding at the beach (or pool), you’ll want to make sure the frames wrap around to protect your peripheral vision. If you’re just running from the car to the house, walking around for limited amounts of time, or casually soaking up the rays, more fashionable frames should be adequate—as long as the lenses offer UV protection. Look for labels that have one or more of these:

• Lenses block 99% or 100% of UVB and UVA rays. 

• Lenses meet ANSI Z80.3 blocking requirements. (ANSI: American National Standards Institute)

• UV 400 protection. (This type of lens will block light rays with wavelengths up to 400 nanometers, which means that your eyes are shielded from even the tiniest UV rays.) 

Polarization

"To produce a polarized lens, usually a tinted film is applied to it that filters most of these reflected rays from your vision, thus reducing or virtually eliminating reflections or glare."

Polarized lenses have been around for years, and many people know that they can enhance vision by reducing glare and reflections, but few actually know how polarized lenses work.

When light is emitted from a source—whether an LED, incandescent light bulb, or the sun—it tends to scatter in all directions, but, when it is reflected off a surface like water, snow, or glass, the light waves become polarized and travel horizontally. To produce a polarized lens, usually a tinted film is applied to it that filters most of these reflected rays from your vision, thus reducing or virtually eliminating reflections or glare.

In the real world, glare and reflection can be annoying at best and dangerous at worst. For drivers, typical reflection/glare can be seen on newly paved roads, dashboard reflections onto windshields, sunlight reflecting from car or building windows or surfaces, puddles, and especially snow and ice. Skiers face a huge problem with light reflected from snow in a similar way that boaters deal with light reflecting from water. Aircraft pilots have to deal with all of these issues, as well.

As great as polarized lenses are, there are some drawbacks or disadvantages to wearing them that you need to be aware of. First, polarized lenses may affect your ability to read LCD or LED displays (such as your smartphone or tablet screen, ATM screens, or GPS). When I say “affect your ability” I’m not referring to the difficulty you have reading your tablet at the pool because of the bright light—it means that the polarized filter will make the screen appear black—as though it were turned off.

 


Non-polarized lenses viewing a stream

 

For a phone or tablet, simply turning the device 90 degrees will defeat the filter, but this issue can occur on certain LCD screens in cars or instrument panels on boats or aircraft—and trying to fly a plane with your head tilted at a 90-degree angle will be as awkward as it is dangerous. Another potential problem polarized lenses pose can occur while downhill skiing. Skiers probably don't want to block light reflecting from icy patches because those reflections alert them to hazards that they are approaching.

 

 


Polarized lenses viewing a stream

 

A common question that is asked is, “How do I know if I’m buying polarized lenses?” The surest way to know—especially if you’re in a store and there isn’t a lot of glare around—is to take two pairs of alleged polarized sunglasses and hold them so that the lens of one is directly in front of a lens on the other. Now, look through the two lenses:

• If you can see through them, rotate ONE of the sunglasses so that the lenses approach 90-degree offset. If the lenses are polarized, you will notice that when the lenses are offset by 90 degrees to each other, you either won’t be able to see through the two lenses or it will be very dark—this is because the polarization filter is canceling all or most of the light coming through the sunglasses. If you rotate the one lens past 90 degrees without noticing a blackout, then one or both of the sunglasses is not polarized.

• If the view is blacked out (or almost black) rotate one of the lenses as you did above. If the view brightens, then both pairs are polarized. You’ll note if the test doesn’t reveal that they are both polarized—there’s a possibility that one is polarized, but it’ll be hard or impossible to figure out which one is and which isn’t. The test will only work if both pairs of lenses are polarized.

In theory, tint and polarization are mutually exclusive and it’s possible to have a perfectly clear lens that is also polarized, but you would be hard-pressed to find a pair like that since almost no one would bother making a non-tinted polarized lens.

Tints

A quick perusal of sunglasses will quickly reveal an array of lens tints. First of all, the tint of the lens won’t tell you anything about their UV protection or whether they are polarized or not. The UV and polarization filters are usually clear, so the tint is a separate consideration of its own.

The tint of the lenses will either filter out certain colors or wavelengths or emphasize them. Here’s a quick rundown on the most popular tint colors, what they do and what they’re good for:

Gray: This is one of the most popular colors because its neutral tint lets your eyes see colors accurately while reducing brightness and glare. Gray is a good general-purpose tint for driving or running and cycling.

Green: Green is a neutral tone like gray, so it will show color accurately. Green also filters blue wavelengths, and as I touched upon earlier, HEV is often called “Blue Light,” so this is an important point. This tint is often recommended for people with eye problems, since stacking a good UV filter with a green tint virtually eliminates the primary causes of sunlight-related problems. Green will also enhance contrast and overall image sharpness while reducing eye strain in very bright light. Those who play sports such as baseball, tennis, and golf tend to favor green lenses.

Yellow/Orange: Yellow increases contrast under hazy, foggy, or low-light conditions. While they help make things appear sharper, they will also cause color distortion, so keep this in mind—especially while driving, because distinguishing changes in traffic lights may be difficult. Yellow is also often preferred by those who engage in snow sports/activities, or for indoor sports like basketball or racquetball. You’ll also find that hunting/shooting glasses come with yellow lenses because of their increased low-light ability and heightened contrast. Orange is virtually identical to yellow’s performance, so it’s mostly a case of personal preference in choosing between the two.

Amber/Brown: These colors are very similar in performance to yellow and orange in that they brighten vision on cloudy days, but they also filter some blue light, so they blend the strengths of both the green and yellow/orange. Looking through an amber or brown tinted lens, you’ll notice an increase in contrast and sharpness—especially against green and blue backgrounds such as grass or the sky. Because of these properties, they are often marketed as driving lenses, usually stacked with polarized lenses. Also, since they are so well rounded, they are ideal for fishing, sports, hunting, cycling, and waterskiing.

Red: Red or light red (also called rose or rosy) block blue light and perform similarly to green. The reddish tint has a tendency to be brighter than green, and is often used indoors by those who sit in front of a computer all day, to reduce glare and eye strain.

Blue: Blue is mostly chosen for aesthetics and doesn’t really have any benefits, as a tint, like the ones above.

Mirrored: Mirrored lenses have a reflective coating on the front of the lens, making them resemble a mirror to someone looking at the wearer. For the wearer, there will be a colored tint that is typically gray or amber/brown. The mirror coating reduces the amount of light passing through the lens by between 10 and 60%, depending on the type and thickness of the coating, so these glasses are often worn by people under intensely bright light from direct sunlight at high altitudes while surrounded by sand, water, or snow. Because of the amount of time spent outside and the lens’s ability to obscure the wearer's line of sight, mirrored sunglasses are often referred to as “cop” sunglasses.

Safety Gear

Beyond protecting your eyes from radiation damage and enhancing your vision while performing sports and activities out of doors, sunglasses are invaluable tools for many tradesmen, military personnel, and police officers. Specially engineered safety glasses will be called on to protect their eyes against everything from wind-blown dust to red-hot slag to razor-sharp shrapnel. At the low-end of the chart would be glasses geared toward laborers, carpenters, construction workers, and weekend DIYers. These are the traditional “safety glasses” that offer impact and shatter-resistant protection from sawdust or falling debris, and even caustic chemicals or acids. At the other extreme of the spectrum would be sunglasses aimed directly at tactical professionals, which provide ballistic protection from flying brass being ejected from rifles or fast-traveling shrapnel from IEDs. For welders and cutters, the eyewear they require is incredibly specialized and beyond the scope of this piece.

Basic Safety Glasses

According to the Occupation Safety and Health Administration (OSHA), “Thousands of people are blinded each year from work-related eye injuries that could have been prevented with the proper selection and use of eye and face protection. Eye injuries alone cost more than $300 million per year in lost production time, medical expenses, and worker compensation.”

With numbers like that, it’s obvious that any time you are around any kind of construction, you’re better off wearing eye protection than not.

Your choice of safety glasses will be greatly dependent on the environment in which you’re going to be working. When I worked construction, I chose a more conventional sunglass style, but with peripheral protection that would stop debris from coming in from the sides. They folded like traditional sunglasses, and fit in a pocket or could be hooked in my hard hat and put on quickly when I was cutting steel, working overhead, or running circular saws or grinders. I had two pairs—one clear for indoor work and one gray-tinted for outdoor work.

If there will be chemicals or other fluids involved, you’ll want to forgo traditional frame designs and go with a full-on goggle that provides a seal around the entire eye area for maximum protection against splashes.

Another point to consider is if you wear prescription eyeglasses. You should never sacrifice being able to see for safety, so you would want to get a pair of goggles that allow you to keep your corrective eyewear on while having the benefits of eye protection. Don’t make the assumption that because you are wearing glasses that they will protect you the same way as ANSI-certified protective eyewear will—they won’t, under most circumstances.

When shopping for your safety glasses, you’ll want to look for ANSI Z87.1 or higher to protect you during construction work. This protection is strictly for impact and shatter-resistance, so you can get them with clear lenses for indoor work. If you’re working outside, look for tints and UV protection—and as I stated earlier, these are mutually exclusive features, so choose carefully and look for UV protection labels.

Ballistic Safety Glasses

Whether you’re in the military, law-enforcement, a recreational target shooter, or a hunter, having the proper eyewear is essential to protecting your vision. While the testing is similar to the ANSI Z87.1 used for commercial eye protection, the requirements to be certified for ballistic protection—especially for military use—are much more stringent.

There are two main Military Ballistic Standards used for testing, MIL-PRF-31013 (spectacles) and MIL-DTL-43511D (goggles). Eye protection that pass these tests are listed on the Authorized Protective Eyewear List (APEL) which shows military and law enforcement professionals approved eyewear for duty use. The minimum U.S. military standard requires that ballistic eyewear always withstand a 0.15 caliber, 5.8 grain, T37 shaped projectile at a velocity of 640 to 660 feet per second.

To give an idea of the difference between civilian and military protective eyewear, the MIL-PRF-31013 testing produces about 7 times more impact energy than the ANSI Z87.1 standard, and the military standards for goggles are even more rigorous. Additionally, these military standards require the eyewear to have UV protection, a reasonably comfortable fit, chemical resistance and environmental stability (resistance to extreme temperature and environmental changes).

As with civilian protective eyewear, ballistic eyewear will be offered in clear and tinted lenses with UV protection and possibly even polarization. But, again, be mindful of what type of electronic gear you’ll be using, because if you’re wearing polarized lenses you may not be able to read your GPS or computer screen and that could be disastrous to a mission’s success.

Essential Part of Your Daily Routine

Whether you’re running errands or running after a suspect, proper eyewear should be an essential part of your daily routine. My wife keeps her favorite pair of sunglasses next to her car keys—she also keeps a spare pair in the console, just in case. When I worked construction, I kept my eye protection hooked in my hard hat so I would always have them handy whenever I need them. Proper eyewear isn’t always about fashion, comfort, or looking like Bono—eyewear protects one of the most exposed, vulnerable and important organs in the human body and proper steps should always be taken to protect them from harmful radiation, flying debris, or any of the thousands of possible hazards that can cause damage or blindness.

 

4 Comments

You may want a follow-up article re. Hearing safety - found it interesting that the worker pictured with the safety glasses lacked hearing protection ... While using a very loud angle grinder...

Please suggest sunglasses that can fit over prescription eyeglasses.

Hi Magoo -

Goggles might be a better choice.  Like those used for skiing.  As far as sunglasses go - you would actually have to try the sunglasses on to ensure a comfortable fit over your existing Rx glasses.  The best solution would be prescription sunglasses. Please see your local optician.