BS EN ISO 12312-2:2015 pdf free.EYE AND FACE PROTECTION - SUNGLASSES AND RELATED EYEWEAR - PART 2: FILTERS FOR DIRECT OBSERVATION OF THE SUN. This part of ISO 12312 applies to all afocal (piano power) products intended for direct observation of the sun, such as solar eclipse viewing. Information on the use of filters for direct observation of the sun...