Wil Wheaton was 8 in A Long Way Home when he played the character 'Donald Branch (8)'.
That was over 42 years ago in 1981.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 51, and has starred in 53 movies in total, 51 of those since A Long Way Home was released.
In A Long Way Home, I think Wil Wheaton looks: