As KmH says, lens cleaning solution is not often needed. But there ARE times when it is super-valuable. Like when? Well, in my area, in the spring time, when outdoors there is a TON of airborne sap from trees that are budding out; this is one of the few times of the year when I will use a UV filter. This airborne sap is very tiny microdroplets, but it does NOT respond to the old huff of breath cleaning...that only liquifies it, and it smears all over.
Another time is when something greasy gets on the front element; You will notice that the link above has a residual grease removing type of lens cleaner. Edmund Scientific used to make a similar product. It's not all that often that it happens, buuuut...airborne cooking oil from deep fat frying or frying of food is one of the most common ways that a lens or camera eyepiece can get a LOT of grease on it, fast.