A top body has warned of the dangers of using novelty horror contact lenses this Halloween.
The College of Optometrists say many of the lenses could lead to painful conditions and eye infections.
And they say that despite their proliferation online and in the high street, it is illegal to sell these lenses without the direct supervision of a doctor, optometrist or dispensing optician.
They claim that people wearing them need to have them fitted properly and know correct eyecare in using them.
Daniel Hardiman-McCartney, Clinical Adviser for the College of Optometrists, said: "Many people think that novelty contact lenses do not require the same level of care as standard contact lenses but this is not the case, even if only worn for one evening.
"We recommend that they should only be purchased from an optometrist who will check they fit well and ensure the wearer knows how to handle and use the lenses safely.
"We also advise that you do not sleep in, or share your cosmetic contact lenses and always wash and dry your hands before touching them."
"It's absolutely crucial that you look after your eyes and wear lenses carefully and as instructed, to ensure your eyes do not become a Halloween horror story."
The College has produced a checklist of safety advice for those thinking of getting spooky lenses.
1. Despite being available from a variety of high street shops and online retailers, it is illegal to sell these lenses without the direct supervision of an eye care expert.
2. Unprescribed novelty contact lenses are not tailored to your eyes, therefore there is an increased risk of developing eye health issues. If the lens doesn't fit your eye properly it may make your eye red, or scratch your eye, leaving it vulnerable to infection.
3. If you wear contact lenses of any kind you must make sure they are cleaned thoroughly after use with the appropriate solution, and disinfected before you put them back in your eyes. Never use tap water, as this may cause a serious infection in your eye.
4. Never share your lenses with other people.
5. Do not drive at night wearing novelty contact lenses that are strongly tinted or opaque. This is because they may impair your vision and increase the chance of an accident.
6. If you experience eye discomfort of any kind when, or after, wearing the contact lenses, you should seek advice from an optometrist, contact lens optician or doctor.