Photochromatic cycling glasses feature lenses that automatically darken when exposed to UV light. Photochromatic lenses can be very useful for cyclists because they help reduce light and increase contrast, which can help with seeing obstacles on the road.
Photochromatic lenses can be a good option for cyclists who often ride in different light conditions and don't always have time to adjust their glasses to the light. So this way, you can get by with a single pair of cycling glasses in all weather conditions!