(optics) a refractive index

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

refraction / inflection

to refract / to inflect (a word) / to be warped

rate, ratio

(business) one on one meeting between an employee and a superior

to lead (something) / to follow / as (someone or something) is / suddenly

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”)