Almost two weeks ago I fell on some ice and hit my head. After falling I did not notice any symptoms of a serious head injury, other than a large bump that covered almos half of the back of my head. There is still a little bump there but it has gotten a lot better. However, on two occasions I have seen a flash of light without knowing what caused it. I have read that flashes like that could be caused by a detached retina. Could a blow to the head like this cause my retina to detach? And if so, could the flashes that I saw be symptoms of that even though there were only two? Or would the symptoms of a detached retina be more obvious?