incident, incidence

lens (object focusing or defocusing the light passing through it)

reflection, reverberation / reflex (automatic response)

reflect, light, sound, radio waves, etc.

a light, beam, illumination / a gleam, glow, ray / a glimmer, shine, sparkle / a luster/lustre, polish, sheen / glory, influence, power / a glimmer, gleam / positive aspect

(optics) angle of incidence (angle that straight line makes with the normal of a surface)

zoom lens (lens whose focal length can be rapidly changed)

a Fresnel lens

Alternative spelling of フレネルレンズ (“Fresnel lens”)

(photography) a wide-angle lens