Harmless. The reasons your eyes may tear when eating spicy foods is that the seventh cranial nerve which is important in the regulation of reflex tear function, also sends nerve endings to the tongue for taste sensation. Capsaicin is a potent irritant contained in spicy foods such as jalapeno peppers. When capsaicin binds to the seventh cranial nerve endings within the tongue, impulses sent along the seventh nerve for the purposes of taste sensation will also stimulate those seventh nerve endings responsible for reflex tearing as well as sweating. In any case, this is not dangerous, but simply a collateral reaction based on the sharing of the nerve pathway.