My therapist/doctor, suggested to combat SAD "seasonal affective disorder" using every morning for approximately 35 minutes, timer function very nice, use the full brightness and daylight color, very bright Properly positioned. No more than 24in away from your face. Eyes opened wide. I would have to give it a five-star rating so far, I have definitely felt as if it has been helping. Have used for about 10 days every morning. At least the cost is cheaper than a bottle of pills every month. Good luck.