Front grilamid tr 90a nylon based translucent ultra lightweight and hypoallergenic material that is co polyamidd approximately 20 lighter than standard plastics and offer superior comfort durability and flexibility injected plastics should always use a cold insert frame adjustments can be made after lens insertion using slight heat not to exceed 40c104fpolycarbonate lensthese lenses are impact resitant lightweigt and provide uv protection polycarbinate lenses also have a scratch resi