How can vitamin B3 help with regulating pressure in eyes and prevent glacouma. So I have read in an article in a weekly magazine. Then I read online that improper use of vitamin B3 can do more harm than good. I begin to wonder if it is of such a good idea to even try it. I am 83 but relatively healthy. My wife, though, much younger and had a bout with acute glacouma that almost cost her eyesight. She was saved by a drastic surgery. But her eyesight is no longer as good as before. She has this fear of that pressure in the eye returning again.