Cleaning Vividia borescope

[Rallylancer122]

I've been using my vividia borescope for a few years now. The picture is getting fuzzy. I'm assuming it probably just needs a good cleaning. Any recommendations on what to use for cleaning the lens that won't wreck it? I've stuck it into some pretty fugly places so it may need more than just a lens wipe.

 

[Stevea]

I’ve used isopropal alcohol to wipe the grunge off after boroscoping engine cylinders. It will not harm the lense or the rubber sleeve. It also flashes off completely without leaving a residue. Use the 90% type….works better than the 50% mix.