Once you get used to that burn you're right, it isn't twice as bad when you add another drop, burn is burn lol!
I agree, my eyes feel great a few minutes after the wash too. The thing that is just so cool about it is that I didn't even realize before I started using it that things looked dull or like BL said like you're looking through dusty windows but you didn't know it lol. Things are just much brighter after the wash.