Following are the possible causes of pinpoint pupils: - prescription narcotics or opioids - hypertension medications e.g., clonidine or tetrahydrozoline - use of heroin - Horner syndrome - anterior uveitis - trauma to head - organophosphate exposure Reference: https://www.medicalnewstoday.com/articles/320350 Image via: https://www.myenvisioneyecare.com/eyes-need-dilated/