DB,
An interesting post.
It is generally accepted that if people have not acquired stereopsis by the age of 8 they will develop a lazy eye.
The interesting thing is that you obviously do not have a lazy eye as from your post it is clear that you can see well with either eye.
I tried to have a look at the forum to which the other guy linked but you need a password for this.
Not an ophthamologist myself but speaking to some at irregular intervals I will ask them next time I do and see if I can come up with an answer.
If you find out in the meantime, let us know.
FD