Those of us that use cameras have to deal with dust that accumulates on the elements, whether that be the back element, or the front element.
Now many years ago when I started out as a photographer, I spent most of my time cleaning the lens elements, not realizing that I was probably doing more harm than good to the glass.
If I saw a speck of dust on the front element, I had to clean the glass, especially the front element of the lens.
It took me a long time to realize that the bits of dust that accumulated on the front element had no impact on the photos that I shot and still shoot.
In fact, if you were to do an inspection of the lens in my camera bags, you would find the front elements can be quite dusty, or worse.
They have to get quite grungy before I clean them, and when I do, I take precautions not to scratch the glass while using my tools of choice for the job. I always carry a can 0f compressed air in my truck, and start by blasting all the loose bits off of the lens for a starter. I then use a camel-hair brush to remove any stuck on dust particles before following that up with a proper cleaning cloth made for cleaning lens elements.
As a rule I do not use lens cleaning fluid, as this fluid can migrate to the inside of the lens element at the edges if your not careful by applying to much. If you do need to use cleaning fluid for a particularly dirty front lens element, apply the fluid to a proper lens tissue, and then lightly swab the lens element.
You may be wondering about the eyeglasses in the photo, and the eyeglass lens require the same care when cleaning them, as the cost of the lens alone in these eyeglasses will buy a nice pro lens for my favorite DSLR!
Needless to say, I use the same cleaning method for my eyeglasses (and sunglasses) as described above.
Of course there is the sensor that resides within the camera body that needs cleaning from time to time, or whenever you cannot live with the dust spots visible in your photos. Most camera manufacturers include software with your DSLR to map the dust particles, and with the tap of a computer key, can wish them gone.
I don't bother with the software, but take the lazy way when editing images, and blip the dust particles that are visible away.
When the sensor in my camera body gets to filty, I finally take the time to manually clean it with tools available from your favorite camera store.
I won't get in to the method I use for cleaning the sensors in my camera bodies, as I don't want you getting on my case as to how you damaged the sensor in your favorite DSLR using my methods for cleaning the sensors!
Your favorite camera store can help you with the tools required for cleaning the sensor in your DSLR.