The wavelength of light causing photophobia in migraine and tension-type headache between attacks

OBJECTIVE: To ascertain the wavelength of light that patients with migraine and tension-type headache find uncomfortable between attacks. BACKGROUND: Photophobia is an abnormal perceptual sensitivity to light experienced by most patients with headache during and, also, between attacks. METHODS: We examined the discomfort threshold to light of low, medium, and high wavelengths in a group of patients with migraine (n=21), patients with tension-type headache (n=19), and healthy controls (n=21). RESULTS: The results indicate that the migraine group had significantly lower discomfort thresholds at the low (P=.001) and high (P=.031) wavelengths compared with both the tension-type headache and control groups; the latter two groups had similar average discomfort levels at these two wavelengths. With the medium wavelength, the control group had significantly higher discomfort thresholds than the migraine (P=.002) and tension-type headache (P=.031) groups; the latter two groups had similar discomfort levels at this wavelength. With unfiltered (white) light, the migraine group had the lowest discomfort threshold and the control group the highest (P=.026), whereas the tension-type headache group had an intermediate discomfort threshold. CONCLUSIONS: There were significant differences between migraineurs, patients with tension-type headache, and healthy controls in the wavelengths that are uncomfortable between attacks.