Definition of optic angle in English:

optic angle

noun

  • 1The angle formed by notional lines from the extremities of an object to the eye, or by lines from the eyes to a given point.

  • 2Crystallography
    The angle between the optic axes of a biaxial doubly refracting crystal.

    • ‘However, it was identified by Kile and Modreski as phlogopite; the optic angle was recently determined to be 16.7 degrees at a wavelength of 589.’