Is UV protection of sunglasses affected by scratches and age?

These are great questions. I will try the best I can to answer completely, but I don't have 100% of your answers. As far as the UV protection goes in the lenses, it really depends on what material the lenses are made of. read more

Therefore, if you drop, scratch, beat up, etc glasses with CR-39 lenses, the UV protection will diminish over time. But with the other lens materials, the protection should hold up regardless of how beat up the glasses get. read more

That protection is essential, because Ultra violet radiation released through the sun could be dangerous to both the back and front from the eye. Contact with Ultra violet radiation may cause photokeratitis, which is sort of a sunburn around the front from the eyes. Also, Ultra violet radiation may cause cataracts and retina damage. read more