Grey photochromic plastic lens, index of 1.56, green coated + UV400 (price per pair!)

What are photochromic lenses? Photochromic lenses change the level of blackout depending on the intensity of sunlight. Indoors, they usually remain colorless and look like ordinary spectacle lenses. In bright light, they darken. This allows them to protect their visual organs from intense solar radiation. Many people who constantly wear glasses with diopters opt for photochromic ophthalmic products, as they correct vision and reliably protect eyes from the sun. Thanks to this, you do not need to buy two pairs of glasses: corrective and sun glasses, as models with photochromic lenses allow you to replace two pairs. As soon as a person enters the room from the street, they become colorless. The degree of darkening of photochromic lenses changes under the direct influence of ultraviolet rays. Ultraviolet light can pass through a layer of clouds and adversely affect the visual organs. "Photochromes" remain dark even in cloudy weather. The main condition for discoloration is direct rays. If a person is driving a car on a sunny day or in a room lit by clear beams, the lenses will remain bright. This is because ultraviolet does not pass through the window pane. There are models that respond to light intensity, and not just to ultraviolet. They will darken in the car or indoors, but the dimming level will not be saturated. Coloring will change by no more than 50%.