Colored contact lenses are the finishing touch to any great Halloween outfit, yet experts are warning about the dangers of the fancy dress accessory, as they could be harming our eyes.
According to the College of Optometrists, the patterned lenses which usually accompany zombie and vampire outfits pose a risk to eye health because unlike the standard version, they aren't fitted by qualified professionals who can advise on how to use them correctly.
If they are not tailored to a person's eyes, the lenses may scratch or cause an infection, particularly if they are not kept clean with the correct solution.
"Most people think that you don't need the same level of care when using novelty contact lenses as you do with ordinary contact lenses, because they don't have a prescription," Daniel Hardiman-McCartney, Clinical Adviser for the College of Optometrists warned.
"It is absolutely vital for the health of your eye that you are able to remove and insert your contact lenses safely, know how to keep them sterile, and have been instructed on how to do so by an optometrist," he added.
The college also urged party-goers not to try cleaning lenses with tap water or share them with friends, as this can lead to eye infections. Driving with tinted lenses that impair vision should always be avoided.
The warning comes after Jess Wilby, a blogger from Manchester, suffered a severe reaction to a pair of emerald green contact lenses in 2015. Jess bought the cheap lenses as part of her Medusa Halloween costume, and despite her efforts to be careful with them, they caused her eyes to swell.
"After just three hours my eyes began to burn," Jess wrote in a blog post about her experience with cosmetic lenses. "It felt like a migraine was coming on. I felt agitated, disorientated and my eyes were extremely red and sore. I immediately went home with my friends and removed the lenses."
After sharing her story, Jess said she had come across many other people who had suffered from similar reactions.
So, if you still want to add spooky eye-wear to your Halloween costume this year, it's well worth following the College of Optometrist's advice.
This article originally appeared on Cosmopolitan.co.uk. Minor edits have been made by the Cosmo.ph editors.