“there is a machloket between Rav Elyashiv zt”l and Reb Shlomo Zalman zt”l as to the permissibility of wearing lenses that change into sunglasses outside (photochromic lenses) on Shabbat. Rav Elyashiv says “No”,it is Tzove’a. Reb Shlomo Zalman says “muttar”, not Tzove’a”
I heard the following story that R Ezriel Auerbach’s rebbitzen (R Elyashiv’s daughter) went into a glasses store and the proprietor showed her a pair of photogray glasses. She said “May father says I shouldn’t wear them on Shabbos, but my father in law says I can”
The glasses store owner (who did not know who she was) says, why are you asking your father or father law, this is a shala for a Rov.