I had always thought that it was impossible to change the distance between the eyes, that it was always fixed. However, skimming through this paper on rapid maxillary expansion, it seems that they measured an increase in distance:
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512012000500022
Points associated with the right eye and left eye moved away from the mid-sagittal plane representing an increase in the distance between the eyes
However I can't find any more info and it's not something I've ever heard people talk about before.
Skull and Jaw Correction
Join hundreds who are Tensegrity Mewing, enhancing the good results of mewing and reversing damage. Free Newsletter and Classes
Your email is safe with us, we don’t spam