With Halloween fast approaching, people have been warned to avoid using novelty contact lenses, as these can pose a serious risk to anyone who wears them.

The warning was issued by CORU, which is responsible for regulating a number of health professions, including opticians and optometrists. It is also responsible for regulating the sale of contact lenses in Ireland.

Currently, it is a criminal offence for unauthorised individuals to sell contact lenses here.

"The only person qualified and permitted to provide a contact lens prescription in Ireland is a CORU registered optometrist, dispensing optician or a doctor. Any other individuals or businesses who sell contact lenses are in breaking the law and could be subject to enforcement action," explained CORU chief executive, Ginny Hanrahan.

She pointed out that while novelty contact lenses may appear harmless, "the reality can be far more serious".

"Common problems associated with unsupervised use of contact lenses can include red, sore or dry eyes. Poor quality lenses or poor hygiene practises can also lead to far more serious complications including severe infections, that in a worst case scenario, could cause permanent blindness.

"We are strongly advising anyone considering novelty contact lenses as part of a Halloween costume not to wear them. In addition we are appealing to parents to discuss these risks with their children and ensure that no young person inadvertently exposes themselves to these risks," Ms Hanrahan said.

She reminded people that contact lenses are a medical device and as a result, should never be used without a valid prescription and appropriate supervision.

"Contact lenses are not appropriate for everyone and those who wear them regularly will be aware of how important it is to follow usage instructions. If novelty lenses are bought from an unauthorised seller, you are not receiving the usage instructions, you cannot know if they are suitable for your eyes and the lenses themselves have not been subject to the required safety checks," she noted.

According to CORU, there are many risks associated with wearing novelty lenses, including:

-Common problems - unsupervised lens use can include red, sore or gritty eyes, dry eyes, sensitivity to light, blurred vision and headaches
-Incorrect base curve - if the lens is too flat, it can feel uncomfortable and cause variable vision. If it is too steep, it can cause stagnation of tears and reduce oxygen to part of the eye, which can result in red eyes and swelling. If it is very steep, the lens can become very difficult to remove
-Reduced vision - Halloween favourites like cats' eyes or blackout lenses can reduce peripheral vision, which can affect mobility, depth perception and balance. This can make driving very dangerous. However, often the packaging contains no warning about such dangers
-Severe infections - many people will not use appropriate solutions to moisten their lenses. Some may even use tap water or saliva, which significantly increases the risk of infections such as bacterial conjunctivitis or a devastating condition called Acanthamoeba keratitis. Acanthamoeba is an organism commonly found in tap water and hot tubs. It causes an infection which can lead to permanent visual impairment or even blindness.

CORU has previously taken enforcement action against retailers for selling novelty contact lenses. If members of the public see novelty contact lenses for sale, they are asked to contact CORU immediately by emailing enforcement@coru.ie.