Question

Why do people often breathe out on glasses to make them wet?Why the glasses become wet?

Answer 1

To clean their spectacles, people often breathe out on glasses to make them wet. ... The gases that we breathe out contain water vapour which condenses at spectacles so glass becomes wet and with the help of small amount of water, it is easy to clean the spectacles.

Answer 2

When you exhale , the water vapour present in your breath condenses on the glasses and hence, the glasses become wet and it is easier to clean them.