The use of HID and LED headlights in the European Union is regulated by the European type-approval system under Regulation (EU) 2018/858, eur-lex.europa.eu/eli/reg/2018/858/oj/eng, transposed by SI 556/2020 www.irishstatutebook.ie/eli/2020/si/556/made/en/print - European Union (Road Vehicles: Type-Approval and Market Surveillance) Regulations 2020. This system establishes technical and safety standards for vehicles and vehicle components for sale or use in EU Member States. To gain type-approval, headlight components and technology must meet specific safety standards. Accordingly, if a headlight has been type-approved and entered into service, it is considered safe to use within the EU.
Factors which can contribute headlamp glare include misalignment, dirty or damaged headlamps or the use of incorrect bulbs. During roadworthiness testing (NCT and CVRT), a vehicle's lighting system is tested to ensure it is in full working order and correctly aligned for the safe performance of the vehicle.
As the standards for these lights are regulated for at EU level, my Department currently has no plans to carry out any study on their use in the State. However, I understand that the UNECE Working Party on Lighting and Light-Signalling, unece.org/transportvehicle-regulations/working-party-lighting-and-light-signalling-introduction, is planning on establishing a task force to investigate this issue.