You don't specify the surgery. But the answers above are typical for modern cataract surgery in the USA.
I agree with yarrow. Totally relaxed and no pain!
For my cataract surgeries, it was less than fifteen minutes for the first eye and about 20 for the second. Of course, the prep--filling out forms and then sitting or lying around waiting beforehand--took an hour or so.
One nice thing, though, in terms of anxiety: As I was lying on the gurney waiting to go into surgery and chatting with the anesthesiologist, with an IV long ago placed in my arm, I thought, "How odd. I don't feel at all tense." I think they gradually add a little relaxing potion while you wait.
If you are talking about cataract surgery, it should be less than half an hour.