Light therapy is the most common treatment option for persons suffering from Seasonal Affective Disorder (Winter Blues), and it is applied using lightboxes that emit the light of a certain wave-length. It has been shown that light therapy is almost as effective as antidepressants for beating the winter blues.

But, What Are The Side Effects?

The side effects of light therapy are very mild and almost never severe. If we compare them to side effects of antidepressants – another commonly used treatment option, we can see that lightbox produces minimal damage. Besides, all the unwanted events caused by the lightbox can be eliminated by changing the exposure time, because different persons have different tolerability to light therapy. So the upper limit of using light therapy is actually the effective dose.

Eyestrain, headache, and nausea are the most commonly reported side effects at the start of the therapy, they last for a few hours after therapy, and they usually go away after several courses of treatment. Therefore, the health care providers usually advice their patients to keep up with the therapy until the side effects subside. If however there is quite a discomfort, the doctor can lower the exposure, or recommend you to increase the distance when sitting in front of the lightbox.

On the other hand, severe side effects are very rare, and they include hyperactivity, restlessness, irritability, and sleeping difficulties (insomnia). Viral infection or simple cold can contribute to worsening of these unwanted events. Those side effects can be very disturbing and may require the termination of the treatment, but fortunately they are not common, and are eliminated as soon as the infection is healed.

Can The Lightbox Damage Your Eyes?

Eye problems can also occur while using light therapy, and they include eyestrain and itching. It has been shown in recent studies that blue component of the light spectrum has a bad influence on eyes. That’s why different glasses are designed to absorb the blue component selectively, without significant change in light intensity.

The quality of lightbox itself contributes to better effectiveness with less side effects. For example, ultraviolet light is very harmful and most of the manufacturers make efforts to filter ultraviolet component of the spectrum. However, some of them do not pay much attention to that, so you may want to check the device specifications before you buy it.

Precautions have to be made in persons suffering from eye and skin conditions, because the exposure to light could affect them in various ways. Special concern is given to patients with diabetes which can damage retina of the eyes itself, so the light exposure risk has to be estimated by the professional.

Can a Tanning Bed Replace the Lightbox?

The answer is no. Some persons with SAD reported the beneficial effects of tanning beds. That has not yet been scientifically confirmed, but it is certainly not recommended. Namely, tanning beds release mostly the ultraviolet light which is damaging and not useful in SAD treatment. It is the visible light that is proven to have the useful effect, so the light boxes which are designed for this specific purpose are highly recommended.


Mayo clinic staff. (n.d.) Light therapy. Retrieved from

Terman, M., Terman, J.S. (2005). Light therapy for seasonal and nonseasonal depression: efficacy, protocol, safety, and side effects. CNS Spectr. 10(8):647-63.

Labbate, L.A., Lafer, B., Thibault, A., Sachs, G.S. (1994). Side effects induced by bright light treatment for seasonal affective disorder. J Clin Psychiatry. 55(5):189-91