1- Clean frequently
Even if you haven't pedaled in dirty places, a little cleaning of the glasses is essential. Remove existing dust with a microfiber cloth.
2- Pay attention to sweating
Perspiration is heavily concentrated in the stalks and bridge of the nose. Perspiration is very corrosive. Wash with warm water and mild soap and dry with a clean cloth.
3- Avoid removing dry mud with your hands
This could scratch the lens. If you are not at home, put some water on the lenses. At home, wash with warm soapy water.
4- Avoid cleaning products
Household cleaners can damage the lens and frame material due to chemicals. Soap and water is ideal to clean it.