Purpose: To quantify intraocular pressure (IOP) change and time course during stressful activity. Study Design: Experimental Study. Subjects: Three nonhuman primates (NHPs). Methods: Bilateral IOP and aortic blood pressure (BP) were recorded continuously, then averaged for periods of 8-30 seconds before, during, and after a common anesthetic induction procedure (cage squeeze followed by intramuscular injection). Experiments were repeated four times in each NHP. Main Outcome Measures: IOP, BP, and heart rate (HR) change during an anesthetic induction procedure. Results: IOP, mean arterial pressure (MAP), and HR increased rapidly and significantly by 27%, 38%, 34%, respectively, in anticipation of anesthetic induction (Figure; p<0.05). IOP rose ~10% within 10 seconds of hearing the technician enter the outer anteroom door, and reached its maximum within ~1 minute of first anticipating human contact. IOP fell to below baseline levels within 1 minute after anesthetic induction. Conclusions: IOP increases rapidly and significantly in response to stressful situations in the nonhuman primate.