I hit my eye/head really hard. i blacked out for a sec. my eye is sore but i have been having head aches. my friend thinks i had a mild concussion.

You may have: Any complete blackout can be theoretically called a concussion but you may have suffered a shock from the pain. But to be on the safe side you must get an MRI of brain to rule out intra-cranial hemorrhage. Is your eye itself sore or the bones around it? If the eye is sore you must see an ophthalmologist. If only the bone are sore you can ask your doctor to order an orbital MRI at the same.