Unlikely it is scatter, unless there is some very bright light source that is directly over her head in those photos.
More likely is they appear blue due to an reflective interference filter coating on the front of the lenses that preferentially reflects on-axis blue light, and passes everything else (i.e., the yellow light). Such glasses are useful because the human eye is very poorly focused for blue light (this is why it’s hard to look at blue LED Christmas lights, which always appear blurry). It’s the same reason shooting glasses are yellow.
No, the lenses generally are molded in blue polycarbonate or a higher-refractive index plastic. A blue lense or filter passes the bluish part of the spectrum; a filter-for blue filter absorbs or reflects it.
Shooting glasses (which appear amber) filter out blue light while these special-purpose medical glasses appear blue and pass blue.