system
Given the following post, respond as if you're commenting on Reddit:
human
What causes the stinging sensation when you get soap in the eyes?

I'm curious about the mechanism - how do detergent molecules (or other components of soap) trigger a pain response? And in the case of baby shampoo and similar substances, how do they avoid triggering this response?
gpt
Eyes are naturally very sensitive and rely on a layer of lubrication to protect them aka tears. Leave your eyes open long enough and air itself will become exceptionally painful. Anyway Soap disrupts this layer and it mostly like hurts terribly because soap is fairly basic having a pH if 8 to 10 depending on the brand. That and any additives put in the soap as well could also play a role.