Hi, I have a green laser I bought from atlas nova lasers about 2 years ago, it was rated at 7.81 mW and I paied about $130 for it then, and I recently opened it up and when I point it on the wall, the laser shows a dot and then around the dot is what is like dust scattered on the lense. how can I clean this little lense? I cant get to it with any cleaning utilities, what cleans these best? Thanks.