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Apr 17 2007, 09:43 AM
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ASF Citizen Group: Elite Posts: 85 Joined: 25-May 06 From: undefined Member No.: 20,871 Your Temperament Score? Trader Rating: 0 (0%) Add Feedback for Logarithm |
Eye Protection
What are your best options? by Logarithm Above all other types of protection, face protection should be the utmost priority of any Airsoft player. Most importantly within that safety category, your eyes require the best protection. This leads into the purpose of this article: to showcase a variety of examples, standards, and qualities of adequate eye protection. Your choice of eye protection is extremely important, as not all types of glasses, goggles, or masks offer sufficient protection for Airsoft. Qualities of Good Eye Protection Let me begin by introducing two common specifications of impact resistance standards which apply to many safety lenses on the market. ANSI Z87.1 This standard was set forth by ANSI (American National Standards Institute) and is intended to ensure that a lens which complies with this standard can resist impact. Many types of eye protection which are readily available on the market do comply with Z87.1 standards. Although ANSI didn’t have Airsoft in mind when creating this standard, Z87.1-complient lenses can resist the impact of an Airsoft BB. Am I sure? To prove that this is true, I shall reveal the impact test that is performed on lenses and compare them to the impact of an Airsoft BB. For basic Z87.1 compliance (Z87.1-1989, the first and minimal specification), a lens must be able to stand up to a one-fourth-inch diameter steel ball accelerated to 250 feet per second at the lens, which may not shatter or fragment any part of the lens or cause the lens to come into contact with the wearer’s eyes in any way [3]. When compared to an Airsoft BB:
Through this data, it is shown that the ANSI Z87.1 standard impact test delivers a little over twice as much force to a lens than Airsoft generally does, meaning that if a lens can stand up to the ANSI Z87.1 standards, they can definitely stand up to Airsoft. Of course, this takes for granted that Airsoft guns that you engage with deliver 3.05 Joules of energy or less. With more force than 3.05 Joules, ANSI Z87.1 lenses are not certified to withstand the impact. To help you determine how hard your Airsoft gun shoots, I shall present a chart (originally posted elsewhere by BattlePriest) which shows the relation between BB weight and Joules, with the appropriate muzzle velocity (in feet per second) at the intersection of each relation. ![]() To make sure you're within the limits for ANSI Z87.1, use this chart to determine what your muzzle velocity is and what the appropriate weight of BB is to stay under 3.05 Joules, since Joules is a much better measurement of force than fps alone. You might also use the FPS Converter that I refer to throughout this article (a link can be found in the "Works Cited" section) to calculate how hard your Airsoft gun shoots. To be safe, your Airsoft gun should not deliver more than 3.05 Joules of energy. Also note that the ANSI Z87.1-2003 standards are even stricter and will also resist the impact of an Airsoft BB up to 3.05 Joules. ASTM F1776 This standard was developed by ASTM (American Society for Testing and Materials) specifically for paintball. This standard is more suitable for Airsoft, as these lenses are qualified to resist much more impact than the ANSI standard for impact. I couldn’t find the ASTM F1776 specifications anywhere (for free), but here’s the math:
This data alone confirms that ASTM F1776 lenses are quite sufficient for Airsoft, unless your Airsoft guns shoot well over 1117 feet per second with .2 gram BBs. In conclusion, it is shown here that either standard will do, and while the ASTM lenses are specifically made for paintball and can take more abuse, the ANSI lenses are put through sufficient tests which show their usability in Airsoft as well. Other Qualities of Good Eye Protection Impact-resistant lenses alone aren’t enough to qualify eye protection as a good choice for Airsoft. Another important factor is a full face seal, which means that your eye protection forms a seal against your face and protects your eyes from all angles. This immediately disqualifies any kind of glasses, such as shooting glasses or shop glasses, as a good choice for eye protection. After all, it is important that your eyes are protected in the event that a BB comes at you from any angle other than straight ahead. It would be naïve to think that this could never happen, as it certainly could. Lastly, you should look for goggles that have a strap that goes around the back of your head to keep them on your face. This is another reason why glasses are not good eye protection. If your eye protection is not securely held onto your face by a strap, then you run the risk of your eye protection falling off of your face during the game, which is definitely undesirable, to say the least. Most goggles and masks do have a strap in the back, so you shouldn’t have a problem with finding this implementation at all whatsoever. In summation of this, when you’re looking at goggles or masks that you think might work for Airsoft, ask yourself the following questions:
If you answered “yes” to every question here, you can determine that the eye protection that you’re looking at is adequate for Airsoft (with the exception of mesh masks, which I’ll cover in the next section). If you answered “no” to any question on the list, then you can determine that the eye protection that you’re looking at is not good for Airsoft. It’s simple logic, but it is important to be able to determine what is sufficient to protect your eyes from Airsoft BBs. Examples of Good and Bad Eye Protection Many different types of goggles and masks are commonly used in Airsoft, and I will present a brief list here. I’ll begin with examples of good eye protection:
Of course, then you have bad eye protection:
While these lists may not be all-encompassing, they do provide a broad view of both acceptable and unacceptable eye protection. I invite anyone who reads this article to expand upon either list with examples that I did not mention. Also, if any of the information presented here is incorrect, I invite you to reply with any correction that you see fit. In Conclusion... Hopefully, this guide will lead new Airsofters to choose adequate eye protection. Eyesight is precious, so I advise anyone who plays Airsoft to choose good eye protection. I also urge anyone who plays Airsoft to require eye protection for anyone that you play with, as it would be a shame for anyone that you play with to lose an eye over Airsoft. On that note, play safe and happy Airsofting! Works Cited [1] - http://www.cimmerians.org/FPS_Converter.html; this calculator helped me convert from grams and feet per second to Joules. [2] - http://home.comcast.net/~dyrgcmn/pball/paintstats.html; this link provided statistics from which I pulled their average weight of a paintball. [3] - http://www.ibwc.state.gov/Directives/Vol4_0702_03_Dir.pdf; page 21 for plastic goggle tests (page 21 of the specification, actually page 25 of the entire PDF), section 10.3.1.2 specifically; this document contains the entire ANSI Z87.1-1989 specification which I referred to. [4] - http://hypertextbook.com/facts/2004/KarenSutherland.shtml; this link provided an estimate for the density of steel which I used to calculate the approximate weight of a one-fourth-inch steel ball. -------------------- I'm a fan of the whole series...
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Lo-Fi Version | Time is now: 12th February 2012 - 12:21 AM |