How long to wait for a brow lift to settle before considering revision?

Dual brow lift, then a blepharoplasty surgery on right eyelid 3 months later. Later the Left eyelid started to settle lower. I went to the doctor and they said I should wait three months. I waited and once I returned he said with since one was done likely caused the other to come down and should wait another 6 months. He said I could go to a plastic surgeon and see if they will do it. With waiting so long said I'd have to do the light test again, stuff for insurance purposes. feel should do it.