The novelty contact lenses can cause serious problems.
Revellers and trick or 'treaters' have been warned not to wear novelty contact lenses for Halloween.
The products, which carry potentially serious health risks, have become increasingly popular in recent years.
However, it is an offence to sell lenses unless a doctor, registered optometrist or registered optician conducts the sale.
There are many risks associated with the wearing of ill-fitting, poor quality contact lenses, including:
Red, sore or dry eyes
Sensitivity to light
Blurred or reduced vision
People also often increase the risk of infection by using tap water or saliva to moisten the lenses.
This dramatically increases the risk of infections which can lead to permanent visual impairment or in the worst cases blindness