of your face and front of your face at the same time. Each lamp has the same power per centimeter, but cover different areas. Having acne all over your face does not mean you absolutely... depending on how far your acne is spread out. The single head unit is typically used for people that have acne on one spot. The two and three head are perfect for getting the sides... need a three head lamp. However, most people prefer not to do three sessions of 15 minutes in front of the lamp. 2. What is the difference between red light and blue light...