Partygoers and trick-or-treaters across Britain will no doubt spend the next few weeks umming and ahhing over their Halloween costumes for this year. Spooky face paint, plastic devil horns and even strange coloured contact lenses may come as part of this – but you may want to steer clear of one item in particular.

Ali Mearza, a consultant ophthalmic surgeon at OCL Vision, has issued a stark warning about ‘unregulated products’ that he claims are circulating social media. This specifically…