Light: A Therapy (and Trigger) for Migraines

The relationship between light and migraines is complicated. Bright lights can exacerbate migraine attacks, and aversion to light is very common during a migraine episode. Evidence suggests that different colored lights affect migraines differently. And in some cases, as with light therapy, the effect may actually be beneficial.

A strategy used for alleviating seasonal affective disorder (SAD) and sleep problems, light therapy is a safe and inexpensive approach that can be combined with other lifestyle habits and medical treatments to soothe migraines as well.

Understanding the differences between colored light rays and their effect on migraines could be the key to unraveling how light therapy may work in alleviating this condition.

Photophobia, which is increased sensitivity to or aversion to light, affects most migraineurs. When you have a migraine, you may feel that lights are brighter than they really are. Bright light can feel like it hurts your eyes, and you might instinctively squint, put sunglasses on, or put your hand above your eyes to create shade.

While it is generally not as debilitating as the actual migraine pain, photophobia can limit your ability to function and interact with others. If you experience this symptom, you may have noticed that you seek out comfort in the dark until your migraine is relieved.

Often, exposure to bright light during a migraine attack can worsen the migraine itself. Researchers believe that receptors on the retina of the eye (called photoreceptors) detect light and transmit signals to the cerebral cortex of the brain, where migraine pain is perceived.

Light rays are seen as red, orange, yellow, green, blue, indigo, and violet. When these rays are all combined (as in sunlight), they make white light. Two colors in particular—blue and green—are of special interest when it comes to migraine prevention and treatment.

Blue light has a shorter wavelength and more energy than other rays of light. It often is a large component of white light.

Sources of blue light include sunlight, cell phones, computer monitors, tablet screens, flat screen LED televisions, LED lights, and compact fluorescent light bulbs. In other words, blue light is everywhere.

This is just one of the possible triggers behind your migraines, of course, but it is often a reason why some migraineurs experience episodes in a work setting where they stare at screens all day.

Green light does not activate retinal pathways as much as blue or other light rays, so it is less likely to induce a migraine. Furthermore, you are less likely to experience aversion or sensitivity to green light during a migraine attack.

One 2018 study found that white, blue, amber, and red lights exacerbated headaches in 80 percent of the participants, while green light exacerbated headaches among 40 percent. And while other colors of light triggered headaches in 18 percent of participants, green light triggered headaches in 3 percent.

Another study published in 2016 found that exposure to green light significantly decreased light sensitivity in a small group of migraineurs. Of the participants, almost 80 percent reported more intense headaches with colored light exposure—all except green. In fact, about 20 percent experienced a decreased headache intensity with green light exposure.

Lifestyle strategies for managing your migraines—in this case, avoiding or getting more of certain kinds of light—can be useful approaches that improve your quality of life. While light therapy may complement traditional migraine therapies, larger studies are needed, especially ones that utilize devices that either specifically emit green light and/or block blue light. That said, light therapy is inexpensive and simple, so you may want to consider giving it a try.