Restylane does not migrate or "move", but can be massaged and softened in position. If the injection is close to the eye socket, the normal response is to absorb a small amount of tissue fluid, which adds to the overall bulk of the filler, meaning less needs to be used. Since the periorbital tissues are much thinner and softer overall than other areas, swelling is more noticeable, and even more care is needed to avoid nodules or undesired swelling. Injection too close to the surface of the (thin eyelid) skin can make any nodularity more visible also, which is why most injectors recommend that Radiesse NOT be used in this area.
Restylane nodules that are persistent and bothersome (that cannot be massaged into the desired degree of softness) and be reduced by judicious injection of hyaluronidase (Wydase), which is an enzyme that can dissolve the HA filler.