Refractive adj. Serving or having power to refract, or turn from a direct course; pertaining to refraction; as, refractive surfaces; refractive powers. Refractive index. (Opt.) See Index of refraction, under Index.
Absolute refractive index (Opt.), the index of refraction of a substances when the ray passes into it from a vacuum.
Relative refractive index (of two media) (Opt.), the ratio of the sine of the angle of incidence to the sine of the angle of refraction for a ray passing out of one of the media into the other.
