"Light therapy that involves only visible light is generally considered safe. Still, the use of phototherapy for people with drug resistant non-seasonal depression can result in a hyperactive state called mania. In these rare cases light therapy must be reduced or stopped and the condition adequately treated.
Light therapy can be defined as exposure to daylight or specific wavelengths of light for a prescribed amount of time in order to treat seasonal affective disorder, acne and a myriad of other conditions. Even though this type of treatment is generally very safe, negative effects may occur.
As a consequence of light therapy, patients can complain of irritability, headaches, eye strain, sleep disturbances and insomnia. Mild visual side effects are not unusual, but remit promptly. Therefore determining the appropriate dose and timing of light is essential in order to diminish the occurrence of such side effects."
Quoted from:
https://www.news-medical.net/health/Light-Therapy-Safety-and-Side-Effects.aspxwritten by Tomislav Meštrović
Tomislav is a medical doctor with a Ph.D in biomedical and health sciences, specialist in the field of clinical microbiology, and an Assistant Professor at Croatia's youngest university - University North. In addition to his interest in clinical, research and lecturing activities, his immense passion for medical writing and scientific communication goes back to his student days. He enjoys contributing back to the community. In his spare time, Tomislav is a movie buff and an avid traveler.