Totally clear when indoor, exposed to UV will turn darker grey. AirFly photochromic grey lenses are made for athletes who move between indoor and outdoor play. They stay clear/light indoors for better visibility, then darken under UV outdoors to cut glare and reduce squinting, so your eyes feel less strained during long sessions. The grey tint keeps colours natural, which helps with fast ball tracking and depth judgement in sports like pickleball, tennis, cycling, and running. Because the lens adjusts automatically, you don’t need to swap eyewear mid-game, giving you smoother transitions, steadier focus, and more consistent comfort from warm-up to match point.