"rays" . "Rays" . "Light ray" . . "Ray (optics)#Special rays" . . . "incident wave" . "optical ray" . "ray of light" . "light rays" . "Ray (optics)#Optical systems" . "Ray (optics)#Interaction with surfaces" . "incident ray" . "aktinos" . "ray approximation" . . "light ray" . . "incident light" . "wave ray" . "Ray (optics)" . "ray (optics)" . . . . "incident" . . . "radius" . "Ray" . . "ray" . "transmitted" . . "Ray (optics)" . "rays of light" . "Light rays" . "light rays or beams" . "Ray (optics)#refracted ray" . "incoming light" .