One of the most heartfelt wishes of any parent is that their children are safe, healthy and happy. So for a mother or father to think that a decision they made has harmed their child in some way is extremely difficult to contemplate.
But that was the situation Sheffield couple Celine and Ben Jackson found themselves in after buying their three sons laser pens as Christmas stocking fillers.
The boys played with them on December 25, but the next day their 10-year-old son William complained of an uncomfortable sensation in his left eye.
As luck would have it, he was due to visit the optician the following day anyway, and after his eyes were checked he was referred to the Royal Hallamshire Hospital for tests.
Doctors at the hospital found he had suffered an injury to the delicate tissue at the back of his eye, believed to have been caused by a laser beam, and soon William’s eyesight began to deteriorate rapidly, causing his parents to fear he would be completely blinded.
Thanks to the expert treatment of city medics, the schoolboy has now recovered, and his family are backing consultants from the Hallamshire and Sheffield Children’s Hospital, who have completed the first study of its kind into eye injuries among youngsters caused by misuse of lasers.
The study has found alarming evidence that some lasers labelled as low-powered, novelty items actually emit extremely strong beams, often many times the safe limit.
Another child who took part in the study - an eight-year-old boy - has been left with permanent laser scars, which he can see constantly at the centre of his vision.
The message is clear - laser products not marketed as novelties should only be used for their intended purpose, while toys should be brought from proper shops and marked with the CE symbol - a European safety hallmark.
After all, our sight is one of the most precious things we have, and would be a terrible shame to lose it to something as avoidable as a laser pen.