Because of the shortness of the light is actually a flash is not dangerous. You but it seems particularly unfortunate to have caught. Very likely, some vision cells in your retina burned. This can actually happen, because light rays are bundled on just a very light-sensitive cells meet. To clarify whether it is just an irritation or an act Enzündung (pain is very unusual), I would go to a doctor. To be able to see me is very important.
That's reassuring!
Go to the doctor anyway. Pain is not normal. A retinal detachment as a result of inflammation is a serious matter.
