Noun: optic axis
- In a doubly refracting crystal, the line in the direction of which no double refraction occurs
"a crystal may have either one or two optic axes"
- A line that passes through the centre of curvature of a lens so that light is neither reflected nor refracted
"in a normal eye the optic axis is the direction in which objects are seen most distinctly";
- principal axis
Derived forms: optic axes
Type of: axis
Encyclopedia: Optic axis