Mildew on inside of Sans & Str...

Once mildew or fungal growth gets into a binoculars you have a major problem. Fungus 'eats' into the glass. Once this has happened the lens or prism needs to be replaced. There have been a number of solutions over the years but non has been able to fix the problem. Even if the fungus is gone there will be an effect on the clarity of vision. Binocular glass is made to be as clear as possible. Sans and Streiff made mediocre binoculars in the early years using BK7 glass with the last ones being quite good in the lower end of the market using BAK4.

Replacement parts are not readily available and the cost would exceed the worth of the unit. Unless is it has some personal significance it is not worth fixing.