Something Strange Happens to Your Eyes When You Breathe

<img width="128" height="52" src="https://www.sciencealert.com/images/2024/07/ExtremeCloseUpOfBlueAndAmberIrisAroundBlackPupilHole.jpg" alt="Extremely close detailed image of a blue and amber iris around a black pupil"/>
We never knew for sure.

https://www.sciencealert.com/something-strange-happens-to-your-eyes-when-you-breathe