Biting my tongue and the inside of my cheek, just this morning, standing in line to pick up my new glasses, while the clerk and customer ahead of me talked about which solvents would be best to keep eyeglasses clean.
I deal with solvents every day. I know which ones take care of oil based and water soluble contaminates. I know which ones are safe to use on anti-reflective coat. But I was good, I stayed quiet.