I just started Ethambutol and Azithromycin. I get my eyes checked by my opthomologist every two months....I also use a book that tests problems with color vision, called, ISHIHARA'S TESTS FOR COLOUR DEFICIENCY CONCISE EDITION 2021 I ordered this on Amazon (I think).....SO I CAN TEST MY EYES DAILY. THE tests the opth does are more extensive. I was concerned about what the drug could do to sight, so this is what I worked out to be able to take it with peace of mind.