What is Photophobia?
Bright lights, big migraine (for some, anyway). Find out what the research says about the link between light and migraines.
• Light sensitivity (also called photophobia) is a migraine symptom for some sufferers
• The optic nerve, which signals light to the brain, could possibly be a player in the link between light and migraines.
• Light is also reported as a migraine trigger for some, particularly bright or flickering light.
Light sensitivity (also called photophobia) is a migraine symptom for some sufferers. Although figures vary, in one large study by the National Headache Foundation, 80 percent of those with migraine report that they are sensitive to light during their headaches.
But exactly how light and migraine are linked is complex, and researchers continue to look for answers regarding why photophobia can be a migraine symptom for some — and why some people even report light (especially glaring or flashing light) as a migraine trigger. 1
Understanding Photophobia and Migraine
For some, light can amplify the pain of a migraine– in fact, some migraine sufferers report that their headache quickly intensifies after being exposed to light, and that the pain lessens after moving to a dark place. 2
Although it is not certain how light exacerbates migraine, research is beginning to reveal some clues. Migraine sufferers appear to be more sensitive to light in general, even when they are not having a migraine. In fact, when compared to individuals without migraines in clinical studies, those who do experience migraines have a lower tolerance to light. 3 Specifically, those with migraines experienced discomfort at a lower light intensity than those without, and their threshold for pain was reduced with light exposure. 4
Another study, though very small, offers intriguing (but inconclusive) results. In a clinical study of 20 migraine sufferers who were also blind, researchers found that the 14 people who did have some light detection remaining felt that exposure to light intensified their migraine. But the six others with no light detection did not report this. Although more studies are needed, this could suggest that the optic nerve, which signals light to the brain, could be a player in the link between light and migraines.
Light as Migraine Trigger
Light is also reported as a migraine trigger for some, particularly bright or flickering light such as sunlight, glare, fluorescent lighting, television or movie screens, and low-resolution computer screens. For example, in a large U.S. migraine population study involving 1,207 individuals with migraine, 76 percent reported that they had triggers for their migraines, with 38 percent of this group citing light as a trigger. 5 And a recent, very small study was done on 16 individuals who claim sunlight as a migraine trigger in and of itself. 6
But to date, studies have been unable to confirm that bright or flickering light can directly cause a migraine in an experimental setting. For example, one recent study exposed 27 patients with migraines with aura to flashing lights, sometimes combined with strenuous exercise, for periods up to 40 minutes in a laboratory setting. Although three participants reported migraine with aura attacks, no participants reported developing attacks from the light stimulation alone. 7 So although many people report light as a migraine trigger, the available data on this is inconclusive.
Remember that triggers vary greatly between individuals, and the best way to find out if exposure to light is a possible trigger for you, or if you experience photophobia during a migraine, is to keep a migraine diary and talk to your doctor with any questions.
1. Hoffman J, Recober A. Migraine and triggers: post hoc ergo prpter hoc? Curr Pain Headache Rep. 2013;17:370-377.
2. Noseda R, Kainz V, Jakubowski M et al. Neural mechanisms for exacerbation of headache by light. Nat Neurosci. 2010;13:239-245.
3. Kowacs PA, Piovesan EJ, Werneck LC, et al. Influence of intense light stimulation on trigeminal and cervical pain perception thresholds. Cephalagia. 2001;21:184-188.
4. Friedman DI, De Ver Dye T. Migraine and the Environment. Headache. 2009;49(6):941-952.
5. Kelman I. The triggers or precipitants of the acute migraine attack. Cephalagia. 2007;27:394-402. http://cep.sagepub.com/content/27/5/394.abstract
6. Tekatas A, Mungen B. Migraine headache triggered specifically by sunlight: report of 16 cases. European Neurology. 2013;70:263-266. http://www.karger.com/Article/FullText/354165
7. Anders Hougaard, MD, et. al. Provocation of migraine with aura using natural trigger factors. Neurology, 2013; vol. 80 no. 5 428-431