Just mere hours ago (6PM local time), I picked up a pair of Radarlock Path Photochromic Oakleys at a major department store here in Seoul. Given that Korea is in the Northern Hemisphere, there was still plenty of sunlight (though not near midday). I hopped on a bus heading home and sat on the side that was getting most of the sunlight while wearing the pair. Initially the lens wouldn't darken, but I chalked that up to there being many apartments on the way home and the bus possibly having UV shielding on its windows. When I got off at around 6:30, I stood in direct, unobstructed sunlight for about 3 minutes, but the lens still wouldn't darken. Today wasn't exactly a cloudless sunny day, if that's of any relevance. So my question is, do photochromic lenses work best during the afternoon and become less dark for lack of a better term as the day progresses, or do I have a dud? I'm going to wait until tomorrow lunch to try again and return it that day if need be.