frustrated 16.5 month toddler?

Kim
My son is 16.5 months and every time he gets "mad" or frustrated when I say no or I say stop he tends to make a fist and smacks his eye:temple area.  He used to just bite his hand but now switched to hitting his eye area.
Is there anything I can do to prevent that? Or just have to wait until he understands "no?"  He is also suffering badly with teething as well.