There are different surgical routes to fixing a retinal detachment so my experience may not be the same as his but here goes.
I had a Vitrectomy and lens replacement, then the retina was reattached with stitches and laser.
Vitrectomy is removing all the vitreous fluid from the eye to allow them to get to the retina.
I needed stitches and laser because it was fully detached and buckled.
Lens replacement is done because when they do a vitrectomy they then put a gas bubble into your eye to hold the retina in place and that gas will more likely than not cause a cataract to form if you don't have an artificial lens.
Surgery was bloody brilliant, they gave me Valium, I was awake throughout and so blissfully wonderfully calm and lacking in any worries it was lovely. I was completely aware, able to have discussions, move as needed, I just wasn't bothered about anything. It took just over an hour, I spent more time waiting for my slot in the waiting room than I did in the surgery, then I was only around long enough to have a coffee and biscuit before I went home.
Recovery was fine but a bit odd. I had to do posturing (look it up as there are different positions based on where the detachment is), for me that meant I had to be face down for 3 days, I was allowed to be upright for a max of 10 minutes an hour, at all other times I needed to be flat on my face or bent at the waist nose parallel to the floor. It's to ensure the gas bubble is pushing against the repair like a plaster, holding it in place while it heals.
Other than that I had a plastic shield overnight the first night, then it was off and I just had a few different drops that needed putting in several times a day for a couple of weeks.
There were 3 stitches in my eyeball which were dissolving ones so no after care on those.
There was no pain but my eye felt dry and was very very angry looking for a couple of weeks. It also took about a week for vision to return as you have to wait for the gas bubble to dissipate and be replaced by new vitreous fluid, you can't see through the gas and it reduces a little each day so it's kind of like you are half submerged in water and can see a bit over the water line.
I had 2 weeks off work and that was plenty, probably could have gone back after a week but I'm office based, if he has a more physical role he may need longer, you are warned not do do very physical sports/exercise for 6 weeks.