Surgery Time/Recovery Time
The surgery for upper eyelids takes approximately an hour. Two or more hours if this includes lower eyelids. You can opt for general or local anaesthesia, though general will cost you a small fortune and is also very inconvenient for the surgeon, as he will want you to periodically open and close your eyes to make sure that the eyelids fold evenly.
Recovery time will take ~2 weeks. You will walk out of the hospital slightly groggy and looking like Frankenstein. The stitches stay in for about two weeks, and you will take lots of painkillers to reduce the inflammation and pain; smear cream on the stitches to reduce the chance of infection; and generally avoid keeping your eyes open. A followup with the surgeon happens two weeks later to remove the stitches, and then a visit six months later to make sure everything went okay. This scenario is only when everything goes well.
As for the brand-new fold in your eyes, it will look abnormally large for the first few months (and give you a slightly buggy goldfish look). A good surgeon will make the fold slightly larger than normal, because over time, the fold settles and lowers as you heal. There is approximately a six month recovery time on this, though if nothing goes wrong, you'll look slightly odd for the first month (but nobody will pinpoint the reason why), and then completely normal starting the second month.
The Actual Process
(This is only the procedure for upper eyelids; if anyone's got a first hand account for the lower eyelids, please feel free to share. This is not a personal account, however; this is partly a) a witness account and b) the slightly embellished words of a friend who went through this surgery.)
The cosmetic surgeon will give you a once over to make sure you don't have any medical problems and then mark up the potential cutting spots with a permanent marker on your eyelids. He'll also inject a temporary sedative to knock you out momentarily (read: just enough so that you can't cry out with pain) so that he can inject local anaesthesia into your temples. A paper mask will be drawn over your face with only your eyes showing, just to reduce the mess you'll have all over your face. This is really all the prep they'll give you.
You'll be awake for all this, so pay attention. Most of the time, your eyes will be closed because the thought of something slicing into you will be a little too much, among other things. When the knife goes for your eyeball, you'll experience a hazy sort of fear, but not a whole lot because that's what the anaesthesia is for.
You'll feel tugging as they cut you open like a ripe fruit. You'll feel blood running down the side of your face. You can, intellectually, understand that the warm blood is running down the side of your face, but you won't feel pain, fear, or anything at all, really...
When you close your eyes, red, green, and blue flowers of color will bloom across your vision; it's the kind of display you see only when you close your eyes and lightly press down on your eyeballs. It's a beautiful sight. Though they seem very pretty, a small thought runs through your head:
I may not feel a thing, but somewhere, somehow, a little tiny part of my brain is screaming.
However...
The cutting is not the worst part. It's when they fire up the torch to burn the fat. In order to achieve a perfect "fold", one must burn the excess fat stored in the eyelid (the excess fat being the reason why you do not have a fold in your eye in the first place) so that the skin folds over properly when you open your eyes. The hissing sound is one thing, but it's the smell of burning fat that really takes the cake.
You'll be reminded irresistably of frying bacon.
Asian blepharoplasty differs slightly from the normal procedure done to non-Asians; aside from the shape of the eyelid, the shape of the epicanthal fold among Asians is also different. The epicanthal fold is a small patch of skin by the nasal area that causes an interestingly shaped crease in the eye that must be accounted for when doing this surgery. This is largely the reason why Asian people will generally go to Asian doctors when going for blepharoplasty; not accounting for the epicanthal fold makes for some very oddly done eyes.
When everything is done, they'll take a needle and thread and stitch you up. They'll also give you some sort of painkiller as the local anaesthesia wears off. They'll smear some sort of ointment over your lids (Bactrin or something similar), give you some painkillers and more bactrin, and cheerfully wave you goodbye to you as they count out the money (read: cash only) you've just handed to them.