Neglected dirt on your lens surface can ruin all the work behind your shots, making your final image awfully spotted or affecting its sharpness and beauty. Regular cleaning and correct maintaining of your lens is a good habit any photographer should have and get used to. However, unlike mere window glasses, the optical glass lenses are made of is a more delicate material. Therefore, the best solution will always be to choose a "lens protection filter (PROTECTOR, UV filter, etc.)" to attach on your lens.
The advantages are numerous: by cleaning the filter's surface instead, no cleaning product will ever make contact with your lens. Also, with the filter attached, the lens will be protected by accidental scratches, impacts or damages, and by simply replacing the filter with a new one, you can always shoot in the most desired and best conditions.
Filters, whatever type is used, need a correct cleaning and maintenance to preserve their good conditions over time. Here find some useful tips and easy-to-follow indications:
These simple steps can be also applied for a correct cleaning of your lenses as well.