Common Side Effects From Light Box Therapy and Ways to Alleviate Them

Photophobia

The light emanating from the light box itself may prove bothersome, inciting a case of photophobia (literally, "fear of light"). If you have this symptom, you may experience a light sensitivity that may even cause eye pain. Associated symptoms may include squinting. You may find that the light is irritating and something you simply feel compelled to avoid. This may lead to looking away from the light excessively and intolerance that shortens the treatment period.

Headache

A headache may result from the use of a light box, especially if you are prone to migraine headaches. The bright light may intensify the discomfort. It may come on suddenly. Some may fade quickly with discontinuation whether others could persist for a prolonged period. 

Fatigue

Curiously, the light box may actually incite a case of fatigue. This may occur if your circadian rhythm becomes shifted inappropriately. Using the light in the evening when you are a night owl, for example, would cause worsened morning fatigue. Your body may suddenly be compelled to sleep later into the morning and as a result, you will naturally feel fatigued at that time with difficulty waking. This would also be associated with difficulty falling asleep at the beginning of the night, or sleep-onset insomnia, as discussed later.

Irritability

In some people, the use of a light box may result in increased irritability. You may find yourself losing your patience with others, becoming annoyed, and unexpectedly snapping at them. This may have negative impacts on professional or personal relationships. There can be other mood changes as well.

Hypomania

There are situations where a light box can actually provoke an episode of hypomania. Mania is a period of elevated mood and increased activity. It often occurs cyclically with bipolar disorder. In predisposed individuals, the light box may cause a milder form of a manic period called hypomania. This may be tolerable, but it could also lead to some adverse behavioral changes.

Insomnia

Finally, the light box itself may cause difficulties falling or staying asleep called insomnia. Again, this likely relates to a shift in the circadian rhythm and the body's desire to sleep. If the light box is used at the wrong time, such as in the evening in night owls, it may result in improper timing and a delay of sleep. This is one reason why it can be important to avoid screen light before bedtime.

Ways to Alleviate Side Effects

Many of these negative side effects associated with light box use might be improved by taking a few simple steps. First, you might simply increase the distance you are sitting from the light box. Additionally, it might be necessary to take short breaks or even shorten the session times. Some devices may allow you to reduce the intensity of the light. By reducing the intensity or the amount of time that you are being exposed, the side effects might go away.

For those with sensitive skin, migraine headaches triggered by light sensitivity, or a tendency to mania such as in bipolar disorder, it may be best to simply avoid light box phototherapy all together.