12 year old seeing dark figures

My 12 year old came to me after a lacrosse tournament and began complaining about seeing a man running past him but when he looks, he isn't there.  He describes it as a short dark figure and was seriously scared that he was seeing a ghost or a phantom.  He has no psyciatric problems, is otherwise healthy and has had an appointment with the opthamologist who found no irregularities in his eyes other than a few floaters which, when described do not match the description of what my son is explaining.  These figures are solid, happen in many different settings many times a day. Other than the disturbance and fear that he is being haunted or having hallucinations, my son has no other symptoms. The opthamologist jumped to ocular migranes (migraines) without much exploration of any other issues.    I've scheduled time with the neurologist because frankly, having a back ground in psychology, seeing things isn't normal.  If it doesn't have a medical cause, its psychiatric and I can't imagine ocular migraines looking like figures running accross the room.  Am I right to worry that this is more than ocular migraines or am I just being an over anxious mom?

[LivingInHope]

Has anyone suggested a brain scan to look for tumors, etc.?  Do you believe in fallen angels?  They are real and they don't always remain invisible.  Another possibility to think about.  Your son has displayed no signs of doing drugs, has he?

[A2B2]

No drugs.  But he is now describing the figures as coming towards him.  He's even put his hands up like to block something from hitting him a few times and lookes startled in my presence and said it was his "ghost".  He is scheduled for an MR and an EKG although the neurologist thought it wasn't likely to show anything and we may need to wait and have the tests repeated somewhere down the road if the symptoms don't disappear.  He's recently started with some tics, vocal and facial which he thinks may be tourettes but isn't sure of the cause.   But he is convinced this isn't psychiatric because his affect isn't congruent with psychosis.