What Treatments Are Best for Hyperpigmentation Under Eyes Post Facelift?

it is difficult to give you a clear answer as to what may be causing the darkness around your eyes without a picture.  Sometimes bruising following a facelift can stimulate the pigment producing cells to make a bit more pigment.  It would be unusual to see this with a facelift in the lower eyelids unless other procedures were involved or the facelift involved a composite lift or some kind of  technique around the eye.  This can  be helped to resolve quicker  with retin-A and  hydroquinone but usually will resolve on its own.   it may take even up to 8 or 9 months. 

Early hyperpigmentation of the lower eyes is common after surgery due to the bruising from the facelift or eyelid surgery. It usually subsides in 7-10 days. If it persists one can consider using hydroquinone treatment in this area until it is gone completely.

Although it is hard to tell without seeing your pictures what you are describing is possibly hemosiderin staining and will not respond to bleaching agents or CO2 laser.  Use of a Q switch laser is your best bet.

I would try a new bleach cream called elure, or hydroquinone in 2% strength by La Roche.  I have yet to see someone sensitive to it.  Just apply a bit with a Q-tip and a thin film once a day will help.  You can also consider Kojic acid 2% and evaluate that.  Also, you should be using a SPF 30 or more under your eyes.

This doesn’t typically happen, but there are some lasers that can be effective for this purpose and getting rid of the hyperpigmentation you are experiencing.