Dark circles under the eyes are usually caused by poor circulation, which creates vascular pooling. Injecting the gas under the eyelid reduces this bluish pooling and replaces it with a blush tone. Poor blood circulation is partially responsible dark under eye circles. Cells in the body release carbon dioxide as waste. Red blood cells take the oxygen you inhale and carry it to tissues, then pick up carbon dioxide. Eventually, the carbon dioxide is exhaled by the lungs. Cryotherapy facials use a blast of extremely cold frequency to treat a variety of skin conditions on the face and neck. These facials are said to help reduce inflammation and promote collagen production, although there is little scientific evidence to support this. The immediate effect is fresher tighter and brighter skin.