Scientists have long studied the size of our pupils to understand attention, emotion and even medical conditions. But now, ...

A new study reveals that pupil size fluctuates constantly during sleep, reflecting changes in brain activation levels.

For the first time, researchers have been able to observe how the pupils react during sleep over a period of several hours. A ...

ETH Zurich researchers found that pupil size changes during sleep, indicating shifts in brain activity. This could help ...

A recent study observed sleeping participants' pupils during sleep, using a new method that could have implications for ...

Scientists have discovered that our pupils continue to change size while we sleep, revealing unexpected fluctuations in brain ...

Researchers were able observe eye movements during sleep over a course of several hours for the first time. Pupil size also fluctuates constantly during sleep, and is linked to the level of brain ...

For the first time, researchers have been able to observe how the pupils react during sleep over a period of several hours. A look under the eyelids showed them that more happens in the brain during ...

For this reason, pupil size is often used in psychology and neuroscience research as a measure of mental effort and attention. For many decades, these three kinds of pupil response were the only ...