Spacial awareness

My 2.5 almost 3 year old boy is really struggling with gaining head injuries. He is constantly falling into things, running into things or bumping his head. He struggles with being around his younger sister too and often head butts her with his head. Granted his head is in the 99th percentile since birth but I am starting to worry about all the injuries to his head. Does anyone else struggle with this? Is it just something he will grow out of? We’ve gotten his vision checked and found out he is near sighted but when we went to the eye doctor they said his prescription was mostly a guess because he wouldn’t sit very still to get very accurate readings. He wears his glasses but I don’t think they help either.