This happens all the time now since an optometrist in Ipswich was convicted for manslaughter by failing to spot a brain condition because a patient had swollen optic discs. Consequently every child +/- adult with unusual appearing optic discs is referred to a hospital due to optometrists fear of litigation.
Short version is that it is 99%+ likely to be perfectly normal or nothing to worry about especially if he has no symptoms but only way to find out now is to go and get it checked!