Re*fract"ive (r?*fr?kt"?v), a. [Cf. F. r'efractif. See Refract.]
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.
© Webster 1913.