Absolutely.  Even the mildest peppers such as poblanos have capsaicin, which is a neurotoxin to humans and can cause pain if you forget to wash your hands well after cutting them and then rub your eye, or any other part of your face.  True story:  I once had to soak cotton balls in milk and stick them up my nostrils because I forgot to wear gloves while cutting peppers and itched my nose.