Any dust or sand should be removed from the lens with a soft oil-free brush. If it’s necessary to remove smudges, fingerprints or stains from the surfaces of the lenses, then the lens should be wiped clean with a oil-free lens tissue or soft clean cotton cloth which has been dampened with alcohol.Ordinary tissues or velvet cloths can scratch the lens surface and therefore, should not ever be used.
You should avoid keeping binoculars in places where there is high humidity or temperatures and also avoid dusty areas. They should be kept in a plastic bag or an airtight container. It’s also a good idea to have a desiccant, such as silica gel, there as well. Binoculars shouldn’t be stored in the case supplied because these are generally affected by moisture as well.
Water condensation and mold can appear on lens surfaces in high humidity. If binoculars are exposed to dampness or wet, they should be wiped dry with a clean dry cloth and then sorted in a cool, dry place. Mold can easily form on binoculars if they are stored for long periods of time in their case.
Waterproof models are designed to be airtight and withstand splashes, rain, high humidity and dust. Therefore the internal structure of the binoculars is protected, even using them in severe conditions.
If binoculars have been exposed to sea water or muddy water, the exterior should be thoroughly rinsed off and wiped dry. (Binoculars should not be left to dry naturally because this can result in changes to the lens surfaces)
To keep your waterproof binoculars in the best condition possible, it is recommended by Nikon that your binoculars are regularly serviced by an authorized dealer