The words tijera and tijeras can be used interchangeably in Spanish to refer to a single pair of scissors.
Both IV sedation (twilight) and general anesthesia are used commonly for cosmetic or plastic surgery. Regardless of technique, the patient's vital signs must be monitored, which include but not limited to heart rate, blood pressure, and breathing rate.
Requirements for having local anesthesia with sedation; your doctor must clear you medically for surgery, you can lie still and you are not claustrophic (there is a surgical drape place over you during the operation). (By the way, most adult eye surgery, including cataracts are performed in similar fashion.