As others have said, it's life changing. Mine was an emergency (acute angle closure) and the hospital brought a consultant from his bed in the middle of the night, as I was losing the sight in my left eye. That was done the very next day and six weeks later my other eye was done. Now just need glasses to read small print.
Unless you choose a general anaesthetic it is all over in about 10 minutes. I think the worst part is thinking about the actual procedure, and having to lie very still, but you don't feel a thing. You will be given a buzzer to press should you feel like sneezing or coughing. I could hear music playing and the professionals speaking quietly to each other. One of them was my friend's daughter, and she'd told me, that if ever she needed the op she'd want that surgeon to do it, so that filled me with confidence.
Good luck and look forward to never having to search for lost specs ever again!