Celluma-led light therapy is a popular treatment for seasonal affective disorder (SAD) and other sleep disorders. It can also improve mood, energy levels, and brain function. However, some people experience side effects that could be harmful. Skin cancer is one of the most significant risks associated with celluma-led light therapy. People who use it often are at an increased risk of developing skin cancer because they expose their skin to UV radiation 24 hours a day. Other side effects include headaches, blurry vision, dry eyes, eye fatigue, and dizziness.