exposed to small fragments. This includes many people who work in manufacturing. Military personnel may be required to use ballistic eyewear especially when in combat. Hunters are also frequent users of ballistic eyewear because of the possibility of a ricochet or the recoil of the firearm that may result in injury. Law enforcement officers also use ballistic eyewear for confrontations. Performance standards There are three standards currently used to test the effectiveness of ballistic eyewear. These include a U.S. civilian standard (ANSI Z87.1 – 2010), a U.S. military standard (MIL-PRF-31013), and a European standard (EN 166, 169, 170 and 172). The U.S. civilian standard for protective eyewear was revised in 2010. The previous version from 2003 was organized by the type of protector. The Z87.1-2010 version is organized by the type of hazard such as droplet and splash, impact, optical radiation, dust, fine dust, and mist. Also, the 2003 version specified that protective products be marked as providing "Basic" or "High Impact" protection. In the Z87.1-2010 standard, there is no longer a distinction between levels of ballistic protection. Products are either non-impact or impact protectors. Products marked as impact protectors must pass all high-impact testing requirements and are marked as "Z87+". Non-impact protectors are those which do not pass all high-impact testing requirements and are therefore marked only with "Z87" (no "+" sign). The U.S. military standard requires (at a minimum) that ballistic eyewear can always withstand a 0.15 caliber, 5.8 grain, T37 shaped projectile at a velocity of 640 to 660 feet per second (approximately 3.8 mm 0.376 g at a velocity of 195 – 201 m/s). For testing, the velocity of the projectile must be verified using sound or optical chronograph methods. The eyewear is put on an Alderson 50th percentile male headform. A 0.002 inch thick aluminum foil "witness sheet" is placed behind the area of impact. This sheet shows whether any small pieces penetrate or come off of the eyewear during the test. The eyewear being tested is hit one time straight on slightly toward the outside of the center of the lens. The eyewear fails the test if the aluminum foil witness sheet is punctured or if the eyewear is cracked. In addition to ballistic performance, the U.S. military standard includes requirements for optical clarity, protection from UV rays, fit, chemical resistance, and environmental stability (properties won’t be changed by exposure to a range of