Do you find that your sunglasses just aren't dark enough on those bright sunny days? Well then these are the glasses for you! They are category 4 sunglasses meaning that they let in less than 8% light. Our glasses go above and beyond to protect your eyes from the suns harmful rays, whether you have a light sensitivity, allergies, or just prefer that secret service style appearance you will not be unsatisfied with the quality and craftmanship of these glasses. They are not suited for dark days and are not recommended for driving or night time use.