A large minority of people continue to wear their contact lenses after the recommended time recommended by their eye care professional.
According to a poll by the Centre for Contact Lens Research at the University of Waterloo in Canada, 40 per cent of people do not replace their contact lenses by the time they should do.
Forgetting the dates was the biggest reason for users of two-week or one-month wear contact lenses to exceed the time limit.
Of two-week wear lens users, 59 per cent wore the lenses for too long.
The top reason for patients who wore their disposable lenses was financial, as they wanted to save money.
Some 1,654 adults in the US were questioned for the research.
Although contact lens materials and design have gotten better in recent years, allowing more oxygen to the eye, it is still advised that contact lens wearers replace their lenses as recommended by manufacturers and their eye care professional.
by Martin Burns