title: [Skiascopic rulers with convexo-concave ("nonastigmatic") lenses].
mesh_terms: D006801:Humans; D007909:Lenses; D019721:Ophthalmoscopes; D012029:Refraction, Ocular
vernacular_title: Skiaskopicheskie lineĭki s vypuklo-vognutymi ("neastigmaticheskimi") linzami.