Phosphene from rubbing the closed eyes where first described at least since Ancient Greece, but I caught myself thinking that I wouldn't want to try it out. So I wonder, how safe it is to actually rub closed eyes or put pressure on the human eye in general? Can frequent but small, or rare but sharp, application of pressure cause myopia or other eye disorders? What is the maximum pressure before the eye is damaged? What happens with the eye if you accidentally hit it?
I remember several times during my childhood accidentally poking myself in the eye with a finger—the experience was very uncomfortable, I couldn't even open the eye for several minutes, but I don't think anything happened to my eyes since then, and my myopia was probably caused by any other factor than pressure damage.