I did a search on 'cataract surgery,' and on the Mayo Clinic website it said you may be given a sedative to help you relax.
I honestly know nothing about this surgery, but I was just thinking back to my colonoscopy in 2011.
I was given the option of either staying awake and watching the screen or having a sedative. Since I had no interest (zero!) in watching my colonoscopy, I told them I wanted to be sedated. That was no problem, and I practically slept through the procedure. I would guess that may be the case with other surgeries, also. These days they have to know that not everyone wants to be fully alert for these procedures, and I found the doctor/nurses who were with me during the colonoscopy went out of their way to make sure I was comfortable. They deal with patients every day, and most of the day, so I think they're very familiar with 'comfort zones.'
Rather than worry, personally, I would phone the doctor's office and talk to a nurse about your concerns, or even leave a message for the doctor to call you. I think they will be very understanding and sympathetic.
Best wishes and prayers for you. I'm sure you will be fine!