Celestron LensPen - Optics Cleaning Tool, Black (93575) One innocent-looking strand of hair strewn across the lens in your photos or astroimages can take hours of clean-up in a photo-editing program, and a greasy thumbprint or smudge on the optics can send an otherwise perfect image to the trash. One end contains a soft brush for removing dust and other particulates from any optical surface. The opposite end of the LensPen will handle the smudges and spots that cannot be brushed away.