Question: do you know why your eyes turn red in pictures

Red eye occurs only when you have your flash on. The camera produces a big burst of light to illuminate the subject and that burst of light goes in through the open pupil of the person you are taking the photo of, and bounces off the back of the eye. There’s a layer called the choroid here which has a very rich blood supply inside the eyeball and that reflects red light back out of the front of the eye and into the camera.