mikve for men

Question

Dear Rabbi, I realize that the Jewish people did not adopt Ezra's decree of men immersing for being a Baal Keri (experiencing a seminal emission). Nonetheless, many rabbis and sages have advised it anyways. If a man does immerse in a mikve -- for being a Baal Keri or for any other reason -- does he need to remove his contact lenses? I understand that women absolutely must remove them. Since immersing for men is not Halacha, I understand that most rabbis would be lenient about something like contact lenses. But I wonder if spiritually, the degree of purification is the same if a man immerses in a mikve with lenses on or not? Thank you as always Rabbi.