Will Swelling Be Inevitable After Restylane Injection Under the Eyes?

It’s not unusual for patients to experience swelling
immediately following Restylane lower eyelid injections.In most cases, this swelling has resolved in
24 hours but may persist for up to 3 to 5 days in rare cases.Lower
eyelid swelling following treatment with Restylane can be a major source of
anxiety for cosmetic surgery patients. It’s important to realize that swelling
resolves with the passage of time and the majority of patients are happy with
their result.Ice
compresses prior to and after injections can help minimize swelling following
these procedures.When patients have important
events in their lives Restylane injections should be performed at least two
weeks in advance.If
you’re concerned about swelling following Restylane injections, it’s important
to discuss this issue with your physician.Your physician should be able to formulate a treatment plan that
addresses your concerns.

As the other panel members stated, burising and swelling are always a potential side effect with these procedures.  Taking this into consideration will help you plan for possible "social downtime."  When having these types of treatments, make certain that the practitioner is experienced and with meticulous technique.  The eye area is a very unforgiving area, and proper placement of the product is needed.  Diligent icing during and after the treatment will go a long ways in controlling any bruising/swelling.

Yes it is inevitable but everyone reacts differently.  In general I would say you could have swelling all the way up to 2 weeks post injection with some bruising.
I generally recommend icing the area for the first 48 hours which decreases the bruising and swelling.
Good luck.