"That is true. I have no interest in damaging my eyes, but I am willing to undergo some discomfort in the pursuit of my work." Crying because of pain or dealing with other unfortunate... leaking... is something he can handle with some time and care. A well-concocted antidote being a feasible option.

He turns a few pages backwards in his notes to a much more specific page. Each note with an added line with numbers, grams, mL, every sort of fraction. It's no surprise that so many go to Octavinelle for potion notes and supplies, is it? "I was considering a mix that would trigger either a potentially painful response, or to concentrate on one's negative feelings to induce tears."

As they'd discussed, potions can do wonders for human and non-human emotions. Negative states just happen to be more useful.