1 文書を見つけるための辞書。

• optic axis, principal axis
• 光学軸, 主軸
• a line that passes through the center 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"
• 光が反射も屈折もしない、湾曲したレンズの中心を通る直線