During routine general anesthesia (not standardized, left to the discretion of the attending anesthesiologist), pupillary pain index was measured one minute before skin incision. Then, variations in heart rate, blood pressure and bispectral index during the three minutes following skin incision were recorded, as well as the occurrence of movements.

Inclusion Criteria:

• patient requiring general anesthesia
• surgical procedure involving a skin incision
• no regional anesthesia
• written informed consent

Exclusion Criteria:

- neurologic or ophthalmic disease

Children under general anesthesia for an elective or emergent surgery requiring a skin incision in a body area not covered by regional anesthesia