Inattentiveness is a common complaint parents have about their children. The question your child's doctor
will have to answer is if his level of inattentiveness is a part of a condition or if it is a part of his normal development. The best type of physician to initially evaluate this is a pediatrician
A child's level inattentiveness must be somehow placed in a spectrum to determine if it is normal or not. A certain amount of inattentiveness in an 8 year old boy is normal, but a some point, this may be a sign of attention deficit disorder. Autism is a disease of poor development of social skills, and inability to develop relationships with people including caregivers. These children also have a very difficult time learning to communicate properly. While inattentiveness is certainly something seen with autism, you would likely notice other symptoms other than just that. Only you child's doctor will be able to tell for sure.
I suggest that you schedule an appointment with your son's pediatrician. He or she can take a more detailed history of your child's attention span and other social and psychological indices. If necessary, your son's doctor may refer him to a child psychiatrist