Cataract Surgery

My brother-in-law just had cataract surgery last month.
I am not sure how I would react to that and how do they clamp ones eyelids open?
I think they do the surgery with lasers these days, which is a great step up from doing it with a scalpel as they did it many years ago.
The thing about lasers that bothers me goes back to the time I worked at Burroughs.
There were times there when I used a laser on micro-chips to blast open shorted circuits.
I could see the tiny micro-sized metal circuits being blasted away with the very short laser firing.
I know the operation has been refined and done thousands of times, but what if the circuit that controls the pulsing of the laser beam were to fail?
Would a continuous laser just start burning down through my eyeball and destroy my eye?
Would it go through the eye and then start melting the gray matter my brain?
My brain is strained enough just coping with daily life; I do not need to lose more cognition than I already have.
I wonder how stoned one has to be to let a doctor start blasting away on his eyes with a laser?
These are things inquiring minds want to know and of course I do too.