3 months after cheek fillers by cannula I woke up with severely swollen eyes which are hard to the touch.

This sounds pretty serious even though late swelling can be seen with Juvederm fillers. I suggest an examination by your injector/physician for an appropriate diagnosis next available appointment.Good luck. Dr. ALDO 

Although delayed allergic reactions and infections can be related to filler injections, it is important to rule out other medical causes such as hyperthyroidism which can present with the symptoms you described.  I once had a patient who complained of severe headaches a month after she had fillers and  her primary care doctor sent her to the ER, they blamed it on the fillers and sent her to an ENT. The ENT also said it was due to the fillers and said there was nothing that can be done and refused to treat her. She came to me desperate because she thought something horrible was happening due to the fillers. I sent her for a CT scan and she had a massive sinus infection that was not treated for almost two weeks because everyone was blaming her symptoms on the fillers. Please have your doctor check your thyroid levels.

This is difficult to determine without pictures and needs an in-person evaluation. I recommend following up with your injector. If necessary, the filler can be reversed with hyaluronidase. See an expert. Best, Dr. Emer