This came up while cleaning my primary yesterday. I'm always really careful not to get CLP and other products on my optic, but my hand slipped and splashed a little on the red dot's mount. I'm not worried about that: It's happened before. But it got me thinking. Even though most battery powered optics have o-rings for the battery compartment lid and adjustment knobs, how impervious are they to solvents and lubricants (particularly the penetrating kind), getting in and ruining the optic? No matter how careful one is, shit happens.