radiance
https://gyazo.com/d0c6ad4ec28d20236ac0110bb1f800fe
source: [Fate/stay nightのセイバーが目をキラキラさせるGIF画像｜無料GIF画像検索 GIFMAGAZINE 690220]
noun
1. light or heat as emitted or reflected by something:
(柔らかな)光, 輝き.
e.g. the radiance of the sunset dwindled and died.
great happiness, apparent in someone's expression or bearing:
(顔に現れる喜び･幸せの)輝き
e.g. the radiance of the bride's smile.
a glowing quality of the skin, especially as indicative of good health or youth.
2. Physics the flux of radiation emitted per unit solid angle in a given direction by a unit area of a source.