The invention provides an optical filter comprising: a. an organic, solar blind filter dye; and b. a UV-transparent, non-scattering and chemically stable substrate. The substrate may be a UV-transparent nanoporous silica glass solid having pores that are substantially filled with a UV-transparent solvent, which has been selected to dissolve said dye and also to match the refractive index of the nanoporous silica glass solid. Alternatively, the substrate may be a UV-transparent inorganic salt compressed to form a solid body. The invention also provides for methods of making these embodiments and an optical device comprising such an optical filter. The filter provides an efficient solar blind filter that is chemically and dimensionally stable.