title: Cross polarized spectacles in photosensitive epilepsy.
abstract: OBJECTIVE
  To investigate the role of cross polarized spectacles in the treatment of photosensitivity demonstrable by EEG.
  
  
  METHODS
  Patients receiving an EEG who tested positive for photosensitivity were invited to participate in the study. The most sensitive light flicker frequency causing a photic response was determined for each patient. Stimulation was repeated with 2 different pairs of spectacles--1 conventionally polarized and the other cross polarized. An EEG was obtained in each case and reported by a neurophysiologist who was unaware of the identity of the 2 types of spectacles.
  
  
  RESULTS
  We tested 19 patients, 8 to 18 years of age. Two patients did not benefit from either pair of glasses. In 17 patients, the photic response was greatly diminished or eliminated by polarizing spectacles. In 1 patient, conventional polarized glasses helped, but the cross polarized spectacles did not. In 6 patients, both types of spectacles were equally effective; in 10 patients, cross polarized spectacles were more effective than conventionally polarized spectacles.
  
  
  CONCLUSIONS
  The role of cross polarized spectacles in the management of photosensitivity in a clinical situation merits further investigation.
authors.affiliation: Department of Ophthalmology, Leicester Royal Infirmary and Northampton General Hospital, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Jain
authors.forename: G
authors.initials: G
authors.lastname: Woodruff
authors.forename: E A
authors.initials: EA
authors.lastname: Bissessar
mesh_terms: D000293:Adolescent; D002648:Child; D004569:Electroencephalography; D020195:Epilepsy, Reflex / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008027:Light / Q000009:adverse effects; D008297:Male; D010775:Photic Stimulation