I can’t say I noticed a difference in perceived light after a stick of IVM but I’ve described before how all the body defenses got more active. More ear wax, cleaned out the sinuses even tho I never had a cold, along with other stuff. And I noticed that I was making much more gravel in my eyes, even in the daytime, not just when sleeping.
I didn’t have any health issues when I took the stick-—just thot I should do it since I’d been telling folks for two years that it was a good idea. From my own experience it’s a good idea to monitor for changes all around. They might surprise depending on ones basic health condition before.