Medically reviewed by Johnstone M. Kim, MD Key Takeaways The pupil controls how much light enters the eye, allowing for clear ...

New pupillometry research reveals how post-traumatic stress disorder (PTSD) may affect both branches of the autonomic nervous system. By measuring how someone's pupils dilate and constrict in response ...

Dilated pupils (mydriasis or fixed pupils) are when your eyes' pupils, which let light into your eyes, become wider. This can happen due to medications used during an eye exam (mydriatic drops), other ...

Picture this, if you will: Aphantasia can be detected with an eye-opening look into our pupils. To first gauge the pupillary reflex of non-aphantasic people, the researchers sought 42 study ...

Opioids usually make a person’s pupils constrict. This is when the black part at the center of the eye gets smaller, reducing the amount of light that gets inside. Typically, pupil constriction ...

The study, led by researchers from UNSW Sydney and published in eLife, found that the pupils of people with aphantasia did not respond when asked to imagine dark and light objects, while those without ...