Personally, I really don't see too many cyclists using lights in the middle of the day. On the other hand I see many cyclists in the early evening ( as the sun is setting ) using lights. Many of those I see the light first but sometimes it will be the cyclist I see first. All depends on the viewing angle, type of lights being, whether high-visibility clothing is being used and the environment in which the cyclist is riding.
When a cyclist is using a rear or front lamp with a good flash mode, those I tend to see first ( as long as I have clear line of sight ).