One never knows until it's uploaded if the nictitating membrane, the "second eyelid", will show but this picture is a good example as I was fortunate enough to get it mid-stream. Curious that it goes from front to back instead of up to down. The membrane gives the bird the opportunity to still see what's going on when they blink, a cool safety feature in a world where danger might be just around the corner. This membrane is more transparent than most I've seen.