Spits Adventure Wear Safety Glasses Expo V Photochromic UV400 Eyewear Transitional lenses Polished Gunmetal Frame (Yellow Smoke Photochromatic);

As with all transitional lenses they will not go from totally clear to super dark. Most transitions will cover a shorter spectrum either going from completely clear to medium shade, slightly clear to medium dark, or medium shade to very dark. Since we were making these as safety glasses the best range for safety work was from almost clear to medium shade dark, enough to take the edge off of bright sun yet be more than clear enough for indoor work.

Keep in mind transitional lenses react to UV to auto darken. The windshield of a car has a UV filter and blocks UV. Therefore the glasses will not work behind a windshield or windscreen where UV is being blocked.

Since Transitional lenses work on a biological process, extreme heat can diminish the transitional effect of all transitions type eyewear. In most cases freezing the glasses can re-activate the glasses.