STANAG 2920 measures ballistic resistance by testing eyewear's ability to withstand high-speed impacts, with results given as the V50 value, which indicates the velocity at which there's a 50% chance of penetration, while STANAG 4296 builds on this by also ensuring comfort, durability, fog and scratch resistance, and compatibility with other equipment.
MIL-PRF-32432 is a U.S. military standardthat outlines the performance requirements for ballistic eye protection, such as goggles and glasses, used by military personnel. It tests not onlyballistic impact protection but alsooptical clarity, anti-fog performance, and overall durability under tough field conditions, providing reliable protection against ballistic threats while maintaining comfort and functionality for the wearer.