Is It possible to Change the Distance Between Adult's Eyes By Surgery?

The usual intercanthal (inner triangle of your eye) distance between an
adult’s eyes is around 2.5cm, or about 1 inch. Altering this dimension can
occur following trauma to the nasal bone and bone of the inner orbit, and with
subsequent repair. Cosmetic alteration intended to increase this distance is
not typically performed. Cosmetic alteration to this region can be performed
when intended to eliminate epicanthal folds in Asian or congenital eye patient populations.
Any surgery around the eye carries a very low risk of globe rupture and
blindness. Ensuring your surgeon adheres to the highest standards of safety and
patient care, by checking that they are certified by the American Board of
Plastic Surgery, is recommended.

The eyes are fixed within the orbits, so you really can't change the distance between them.  However, if there is wide tissue between the eyes and the nose you can address this surgically.  Any eyelid or orbital surgery carries risk for blindness, but the probability is very low.