title: The wavelength of light causing photophobia in migraine and tension-type headache between attacks.
abstract: 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.
authors.affiliation: European Institute of Health and Medical Sciences, University of Surrey, Guildford, Surrey; Kings Headache Service, London, England.
authors.forename: A
authors.initials: A
authors.lastname: Main
authors.forename: I
authors.initials: I
authors.lastname: Vlachonikolis
authors.forename: A
authors.initials: A
authors.lastname: Dowson
mesh_terms: D000328:Adult; D004056:Differential Threshold; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008881:Migraine Disorders / Q000150:complications*; D020795:Photophobia / Q000209:etiology*; D018781:Tension-Type Headache / Q000150:complications*