OPN4 and Photophobia: The melanopsin signals affect visual discomfort(Spitschan et al., 2017) and the feeling of being dazzled(mabushisa; Higashi et al., 2022) as well as pupilresponses (Gamlin et al.,2007), and photophobia and reflexive eye closure in migraine (Kaiser et al., 2021; McAdams et al., 2020).Although the melanopsin signals also affect brightness perception (Brown et al., 2012; Yamakawa et al., 2019),they seem to contribute more to visual discomfort and nonvisual responses such aseye blink and pupil responses than to bright perception.