Assertion: distance | /r/HasProperty | multiplied by refractive index of the medium
Facets:
Source sentences:
text: If the surrounding medium is not air, then the distance is multiplied by the refractive index of the medium (n is the refractive index of the substance from which the lens itself is made; n 1 is the refractive index of any medium in front of the lens; n 2 is that of any medium in back of it).