Agree with you completely in paragraph one and mostly with the second. If someone said that removing your glasses results in “massive” improvements, that’s a bunch of bull. My experience with this suggests that a very small change is detectable only under the right conditions such as you cited with low or no light, and a bit of alcohol. Any more than a little bit and all bets are off on hearing subtle differences and it’s time to turn Humble Pie up to eleven!
Ever hear of Peter Belt? If you want audio wackiness at its finest check him out. An example: write your name on a piece of paper and place it in your freezer for better sound. Really!!