Response: Lenses protecting against photosensitivity violate international driving regulations

Drs. Bender, Lagrèze, Hirsch, and Schulze-Bonhage raise excellent points about the danger of driving with blue glasses, particularly the Zeiss Z1 lenses. We did advise to “avoid lenses that make it hard to proceed with orange traffic lights.” The letter correctly indicates that any spectacles that darken the field of view or potentially affect perceiving taillights or traffic signals can present a driving danger. Rather than just stating a caution, we might better have said that driving with dark glasses should be prohibited and that doing so is contrary to traffic regulations in several jurisdictions. For those interested in more detail about this issue, regulation ISO 12312-1:2022, the current international standard for sunglasses, categorized commercial sunglasses into five groups (0–4), depending on visible light transmission (VLT). Standards vary among countries, but the following table indicates a common European standard: The Z1 lens transmits 20% of luminance (Capovilla et al., Epilepsia 2006;47:529–533),1 making it unsuitable in general for nighttime driving. Japanese industrial standards determined appropriate VLT of lenses as ≥8% in daytime use and ≥75% in night and twilight use for driving. Train conductors in Japan are permitted to use polarized sunglasses, but not colored sunglasses that can interfere with recognition of traffic signals. Although driving automobiles with dense tinted lenses is not illegal in Japan, it is dangerous, and more public education is needed. Various special glasses can inhibit the photoparoxysmal response while maintaining varying degrees of visible light transmission (Takahashi et al., Neurology 2001;57:1767–1773).2 However, protective lenses with VLT better than 75% have not yet been developed and tested. In conclusion, Zeiss Z1 lenses should not be used by drivers given the risk of missing orange traffic lights, such as taillights. Driving with dark sunglasses is contrary to traffic regulations in many jurisdictions and is unsafe at night. Dark, polarized, or blue lenses may be useful when viewing media, visually provocative stimuli, or as a passenger in a moving vehicle, but not when driving. RF received support from the Maslah Saul MD Chair, National Institutes of Health (NINDS; 1RO1NS137650), NaviFUS, the James and Carrie Anderson, the Steve Chen, and the Pilliod Funds for epilepsy research. FMB received research funding from NINDS K23NS116110, the Doris Duke Charitable Foundation, the Rita Allen Foundation, the Wu Tsai Neuroscience Institute, and the O'Farrel-Principe family. JS received funding from the National Institutes of Health, National Science Foundation, Department of Defense, Shor Foundation for Epilepsy Research, UCB Biosciences, NeuroPace Inc., SAGE Therapeutics Inc., Serina Therapeutics Inc., LivaNova Inc., Greenwich Biosciences Inc., Biogen Inc., Eisai Inc., and the State of Alabama. KNT acknowledges support from the European Union for a Marie Curie Excellence Chair position in Sapienza University, Rome, Italy (MEXC-CT-2005-24224: Visual Sensitivity) and for continued working with the Roman and Italian (child)-neurologists on this subject. R.F. has no disclosures relevant to this paper but has stock options in Avails Medical, Eysz, Irody/CareTuner, Smart Monitor, and Zeto. L.L.T. is on the editorial board for Neurology and is a consultant for the Epilepsy Study Consortium, serving as a consultant for Anavex Life Sciences Corp, Eisai, GW Pharmaceuticals, the LouLou Foundation, Marinus Pharmaceuticals, Ovid Therapeutics, SK Biopharmaceuticals, Stoke Therapeutics, Takeda Pharmaceuticals, and Zogenix. J.F. receives salary support from the Epilepsy Foundation and the Epilepsy Study Consortium for consulting work and/or attending scientific advisory boards for Acadia Pharmaceuticals, Access Industries, Acuta Capital Partners, AFASCI, Agrithera, Alterity Therapeutics Limited, Angelini Pharma, Autifony Therapeutics Limited, Axonis Therapeutics, Bain Capital, Beacon Biosignals, Biogen, Biohaven Pharmaceuticals, Bloom Science, Bright Minds Biosciences, Capsida Biotherapeutics, Cerebral Therapeutics, Cerecin, Cerevel, Ceribell, Cognizance Biomarkers, Cowen and Company, Crossject, EcoR1 Capital, EG 427, Eisai, Encoded Therapeutics, Engrail, EpiMinder, Epitel, GRIN Therapeutics, Harmony/Epygenix, Ionis Pharmaceuticals, iQure Pharma, IQVIA RDS, Janssen Pharmaceutica, Jazz Pharmaceuticals, Leal Therapeutics, LivaNova, London Research & Pharmaceuticals, Longboard Pharmaceuticals, Maplight Therapeutics, Marinus, Medscape/WebMD, Modulight.bio, Mosaica Therapeutics, Neumirna Therapeutics, Neurelis, Neurocrine, Neurona Therapeutics, NeuroPace, NeuroPro Therapeutics, Neuroventis, Neurvati, Noema Pharma, Ono Pharmaceutical Co., Otsuka Pharmaceutical Development, Ovid Therapeutics, Praxis, PureTech, Rapport Therapeutics, Receptor Holdings, Rivervest Venture Partners, Sage Therapeutics, SK Life Sciences, Stoke, Stream Neuroscience, Supernus, Takeda, Taysha Gene Therapies, UCB, uniQure, Ventus Therapeutics, Vida Ventures Management, and Xenon. J.F. has also received research support from the Epilepsy Study Consortium (funded by Eisai and UCB), Epilepsy Study Consortium/Epilepsy Foundation (funded by UCB), GW/FACES/One8Foundation, NINDS, and Praxis. She is on the editorial board of Lancet Neurology and Neurology Today. She is Medical Director for the Epilepsy Foundation. She is the President and on the board of directors for the Epilepsy Study Consortium. She has received travel/meal reimbursement related to research, advisory meetings, or presentation of results at scientific meetings from the Epilepsy Study Consortium, the Epilepsy Foundation, Biohaven Pharmaceuticals, Cerebral Therapeutics, Ceribell, Cowen and Company, Harmony Biosciences, LivaNova, Longboard, Maplight Therapeutics, Neumirna Therapeutics, Neurocrine, NeuroPace, Neurvati, Praxis, Rapport, Supernus, Takeda, Ventus, and Xenon. J.S. has worked as a consultant and/or served on advisory boards for PureTech Health, Biopharmaceutical Research Company, LivaNova, UCB Pharma, AdCel Pharma, and iFovea; and is Editor-in-Chief of Epilepsy & Behavior Reports (paid). B.T.'s institution receives research funding from the C.G. Swebilius Foundation. D.K.-N.T. reports no disclosures relevant to this paper but has served as a consultant in the past 3 years for Jazz Pharmaceuticals, Praxis Precision Medicines, NeuroPro Therapeutics, and Axonis Therapeutics. She receives royalties from Wolters Kluwer Publishers (UptoDate). None of the other authors has any conflict of interest to disclose. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines. This article is linked to paper by Fisher et al. To view this article, visit https://doi.org/10.1111/epi.18702.