Why do glasses become cloudy?

Dull spots on glasses are caused by:

Skin and oil residue: Glasses are in constant contact with fingers and face.
Limescale: Hard water used for cleaning can leave white marks.
Dust and dirt: Daily exposure to the outside environment.
Chemical build-up: Some unsuitable cleaners can make the problem worse by leaving residue.
The magic ingredient: White vinegar

White vinegar is the perfect natural ingredient for cleaning glasses. Thanks to its acidic properties, it effectively removes stubborn residue, dissolves limescale deposits and restores shine to lenses without damaging them.