E! Illustration/AmazonRed light therapy has become a must-have at-home skincare device, trending for its anti-aging and acne benefits. Now, Amazon's Summer Beauty sale is making these devices more affordable. But before you buy, we chatted with board-certified dermatologist Dr. William Kwan to determine which red light therapy face mask Amazon deal is actually going to be worth it for you. What are the benefits of red light therapy? "Red light has been studied for years and has been found to be helpful for fine lines and wrinkles, skin tone, and acne," says Dr. Kwan.