How 3D movies look, to a steroblind person?

[Auntie C]

Hi, everyone. I've got a bit of a dilemma: my 7 year old son has been
invited to a friend’s birthday party, where they will be taking the
kids to see the 3D version of the movie “G-Force”, and my problem is
that I think my son may be stereoblind (he had surgery when he was 1
for strabismus, and had to wear a patch on one eye for hours every
day, for years. He is no longer cross-eyed, but his ophthalmologist
said that it is very possible that he may never have true 3D vision,
a.k.a. “steroblindness”.) My concern isn’t really that he won’t get
the 3D effect when he sees the movie- it would be perfectly fine if
the movie just looked to him exactly the same as the standard 2D
version. Rather, my worry is that the movie will look messed-up to
him (like for example, as if you looked at those older 3D images
without the glasses that had one lens green and the other red, so that
you saw all the extra red and green on the image. So basically I’m
afraid that since his eyes won’t be able to process whatever extra
stuff is added to the images to make them appear 3D, the added 3D
stuff will instead totally screw up the appearance of the movie to
him.) By any chance, is there anyone out there with steroblindness
who has seen a recent 3D movie, and can describe what that experience
was like? Thanks!