Your pupils slightly dilate when there is a rise in heart rate, a reflect caused by the amygdala. They constrict when there is a drop in heart rate. This means when you are excited or in love, your pupils are slightly bigger than when you are relaxed or sad. Drugs play a similar role with your pupillary reflexes: individuals intoxicated with “uppers” such as cocaine, MDMA, and methamphetamine will present with dilated pupils (mydriasis). While individuals intoxicated with depressants like alcohol, opioids, Xanax, and barbiturates will present with pin point pupils. This is why examining an individual’s pupils gives physicians and law enforcement quick knowledge on their vitals and heart rate.
Written by: Student Doctor Navpreet Singh Badesha
