By Nigel Little 

Ortho-k lenses  which are only worn overnight while sleeping and hence for only 6-8 hours offer a way for short-sighted people to avoid excessive wear of their daytime contact lenses as revealed in a recent study initiated by leading manufacturer Bausch and Lomb. The study covered 2,000 daytime contact lens wearers of whom half admitted that they wore their lenses for some seven hours longer than the wear time recommended by their optician. Indeed, some twenty per cent of respondents had worn their lenses for a full 24 hours longer than advised. Overall, ninety per cent of the survey population admitted regularly leaving their daytime lenses in longer than their optician advised.

Wearing contact lenses is typically a choice determined by a person's lifestyle and their preferences from an appearance standpoint which often means that daytime lenses will be worn from early morning through to late evening - and sometimes even overnight - because the wearer does not want to revert to glasses either during their work or leisure time. As such, the true wear time may average over 15 hours every day which opticians recognise can lead to significant comfort and even serious eye health problems. By contrast, the small custom-designed ortho-k lenses  only need to be worn overnight since they correct short-sight by using the mild pressure of closed eyelids during sleep to gently reshape the cornea in order that - after the lenses are removed in the morning - light focuses directly on the cornea rather than in front of it.

The correction effect of overnight ortho-k lenses lasts for over 24 hours after the lenses are removed so the wearer enjoys perfect natural vision all day long until reinserting them at night. By contrast, the Bausch and Lomb study revealed that fifty-seven per cent of respondents suffered from gritty and uncomfortable eyes, forty-three per cent reported itchy eyes, thirty-one per cent complained of blurred vision and nineteen per cent admitted to having bloodshot eyes. Given these high levels of adverse responses, it is no surprise that drop-out rates from daytime contact lens wear are so high at well over twenty per cent every year. However, the emergence of ortho-k lenses  offers a new treatment for short-sight which can address the excessive daytime lens wear problem and still satisfy people's lifestyle and appearance objectives.

Check if you are suitable for overnight ortho-k corrective contact lenses .