Pupillometry

Pupillometry is a way to measure how big or small someone's pupils are. Your pupils are the little black dots in the middle of your eyes.

When your pupils get bigger, it means that your eyes are trying to let in more light. This can happen when you go from a bright room into a dark one, or if you're trying to see something in the dark. When your pupils get smaller, it means your eyes are trying to block some of the light. This can happen when you go from a dark room into a bright one, or if you're trying to focus on something close up.

Pupillometry uses special tools called pupillometers to measure how big or small your pupils are. This information can help doctors and researchers learn more about how your brain and body are working. For example, they might use pupillometry to see if you're feeling stressed, or to measure how much pain you're feeling. They can also use it to see if your eyes are working properly.

So basically, pupillometry is a way to measure how much light your eyes let in, and it can help doctors and researchers learn more about how your body works.