Restylane Lyft in cheeks resulted in a black eye (Photo)

Filler no matter where it is injected may cause some bruising.  This is a very common side effect.  The bruising you experienced is completely normal and should resolve within 2-3 weeks. 

You definitely had some bleeding in the subcutaneous tissues.  Arica can help resolve this more quickly.  Anti-inflammatories and ice should be fine at this point for swelling.