I have had cataract surgery in both eyes. Will surgery in upper and lower lids be safe?

You should try to wait at least 3-4 months.   Some patients will get a little ptosis after a cataract extraction from the lid speculum stretching the muscle.  This will often resolve after a few months.  If you have no ptosis you could do it sooner. 

It is best to discuss with your ophthalmologist but in general, it is safe to undergo eyelid surgery about 3 months after cataract surgery although it could be done as early as 1 month.