Cleaning Your Laser Lens
Keeping your lens clean will make your machine work more efficiently and provide better results.
Dust and stains on your lens can cause scattering, and impurities on the surface can react with incident laser light to damage optical coatings. I have seen lens actually crack from debris on the lens and it wasnt caught quick enough. Much of this can be avoided by using proper air assist blowing air through the nozzle keeping a positive pressure blowing out and keeping the bad stuff away.
You should handle your lens in a clean, low dust enviroment. You should avoid handling the lens with your bare hands. They recommend using gloves. Latex gloves work well and help with gripping the lens.
You should always dust with a canned air duster, compressed and filtered air, or nitrogen before wiping any optic. This keeps you from scratching the lens by rubbing dust across the lens.
If your lens is dirty, proper use of solvents can often do the trick. I have seen some recommend lens tissue. Most eye doctors will tell you not to use anything paper based on coated optics but instead a lint free cloth. I have found a q-tip soaked in solvent, alchohol, etc does the trick nicely.
As always follow the mfg. recomendations