Do you mean lens replacement surgery for cataracts ?
I had both eyes done with new multifocal lens's (sp?) at BKK Pattaya.
If only getting one eye done at a time was told no overnight stay, if do both at same time then overnight stay.
I opted for both at same time due to having to return to work, they did first eye, waited 10 minutes to confirm I could see ok from that eye then did the second eye.
Surgeon and staff were all excellent, now fully sighted again and hopefully never need glasses again, more than happy with the outcome.