why do person blow on his or her spectacles to wipe and clean
Answers
Yes, I have seen my grandfather blowing on his spectacles, to wipe them clean. The air blown from the mouth is hotter than the glass of the spectacles. ... When the moisture touches the colder glass surface it turns into fine water droplets. These water droplets help in cleaning the glass.
Answer:
Yes I have seen some people blow air onto the spectacles to clean them. The moist from the air blown gets converted into droplets of water on the glass and hence can clean the spectacles.
Explanation:
The air blown from the mouth is hot and the glass of the spectacles is comparatively colder. The hot air we breathe out contains water vapors which turn into tiny droplets of water when it comes in contact with the colder glass. This makes the glass moist and hazy. And hence, this helps in cleaning the spectacles!