This model features photochromic lenses that change color in response to UV light. It's a crown pantos style, popular in French vintage designs, redesigned to fit Japanese faces. PHOTOCHROMIC-LENS (Photochromic Lens) Photochromic lenses are characterized by their changing color density in response to ultraviolet light. They darken in strong UV light and lighten in weak UV light. The advantage is that they can be used as sunglasses outdoors during the day and as eyeglasses indoors, where there is almost no UV exposure, making them suitable for touring with a single pair of shades for both day and night. In addition, photochromic lenses generally have a high UV cut rate of 99% or more, which is gentle on the eyes and reduces eye fatigue. A hard case and glasses wipe are included. No discounts are available.