I was laying outside getting some sun. the sun was almost directly over head and i was blocking out the sun with my hands with my arms extended fully. i obeserved a small white dot slowly come into my view above me at about 500 feet in a north - south direction and as i focused on it after getting up from a laying down position, it suddenly stopped mid-flight and reveresed direction and erratically zig zagged away! i was stunned really because it seemed to react to my seeing it but it seemed so far away or maybe it was very small in size. when it first came into view above me, i wasn't even thinking "ufo" as it was just a white dot which could have been anything really. but i was just amazed that whatever this thing was, moved as fast as it did when it reversed direction and disappeared! i thought about how a balloon would move if at that height and i could see a balloon change direction in the wind for sure but this sphere\orb accelerated so quickly as to challenge any conventional drone or other air device. i read reports of orbs and ufo craft reacting to human observation but never experienced it before this sighting. pretty cool. thanks!