For the red dot to be clear, it would have to be held in the near vision zone (0-40cm.)
No,no,no. You do not focus on the dot with a red dot optic, you focus on the target and look "through" the dot, when you do focus on the dot and your astigmatism makes it look "not round" you are sure to have poor results.
Been through all this starting circa 2005. Glasses & contacts didn't work for me, so eventually I had Lasik monovision done (2008), right eye near left eye far and it was wonderful (be careful here, before agreeing to Lasik monovision a good doctor will make you try it for a couple of weeks with "extended wear" contacts, as not everyone can adapt to it). I tried both options and much preferred right eye (dominant) near. But circa 2013 my "far-sightedness" progressed to where the left eye was out of focus everywhere and my right eye was perfect at distance and with the change my ability to use iron sights without "reading glasses" evaporated so I made a pretty complete switch to red dots, and had my left eye Lasik redone for near vision -- my "walking around vision" has been outstanding among people old enough for Medicare, I only really needed reading glasses for long term comfort, or when doing computer or other detail work.
Starting last year my left eye has remained stable but my right eye progressed to nothing in focus, so last week I had Lasik redone on it for near vision -- looks like I can use iron sights effectively again! Yesterday was my first time out post-op, only shot .22lr, but using a red dot was fine, no change of zero and was drilling 3" plates at 25 yards although there were lots of new "details" in the dot I had to ignore when looking through it. Removing the red dot and using the irons was amazing! After adjusting the irons I was hitting the same 3" plates at 25 yards almost as good although had to shoot slower, I suspect speed will return as my brain finishing its re-adaptation.
So, if you have no problems with monovision and wearing contacts just get an extra set to allow good focus on your front sight when shooting.