I have a friend who's pupil, of only one of his eye balls, makes a perfect square shape (90 degree angles) when there is full light in the area. His focus for daylight creates a curious looking pupil, what sort of things could cause this? I've never seen or heard of such a condition before, perhaps it is just a birth defect? How/why would human genes decide to create a pupil with 90 degree angles when focused? I had the idea that the human body is a rounded device, with curves and no sharp angles like this anywhere. Truly a funny anomaly.