ANSI is the American National Standard that covers the basic requirements for personal eye as well as face protection to minimize e.g. accidents from impacts.
EN ISO 12312-1
EN ISO 12312-1:2013 is the European Standard that specifies the special requirements (mechanical, optical, and so on) for sunglasses and sunglare filters for protection against solar radiation for general use etc.
The eye protection regarding the professional life is regulated with the norm EN166. It is the standard European norm for the personal eye protection specifications which classified the eye protection in detail.
MIL-PRF-31013 is a US military standard for spectacles and special performance protective eyewear to test its ballistic effectiveness.
The NATO abbreviation STANAG stands for Standardization Agreement which sets up conditions, terms, technical procedures etc. between the alliance members. This test which is called V-50 is the adaption of standards for ballistic protection levels / testing of a glass that is shoot with a special buckshot. The result of this special testing and the calculation of the V-50 value is called the arithmetic means of the tempo.