When you ride thru the urban jungle, you need not only the head protection but eye protection. The IVS is certified to the eye glass standard (BS EN ISO 12312 – 1 : 2013) offering wind and UV protection. It is made from shatter resistant polycarbonate. The IVS can be used by pulling on the tab and extend as far down as needed. it comes in clear fro cloudy days and also smoke for sunny days. And if you do not want to use the IVS, you can push it back up into the helmet and then you have a standard helmet offering the same impact protection as other helmets. The IVS is designed to be used with eye glasses.