My son, who is now 17, played football from 6th grade through 11th. For the past couple of years, he has had a harder time with schoolwork (motivation, concentration and comprehension) than he used to, which I attributed mostly to puberty. However, the other day he was talking to me shortly after waking up from a nap, and I noticed that one pupil was dilated and the other was not. It concerned me. It also reminded me that he had come to me after practice one day, probably two or three years ago, and had this same issue--but it was more pronounced that day. I asked him a battery of questions at that time and watched him over the next 24 hours, and he seemed okay. I m wondering, though, in that context, if his concentration and comprehension problems could be the result of an untreated head injury. I m not even sure who to see about something like this.