By Michael Hutton 

Corrective contact lenses  worn only while sleeping and not during the daytime will be a key means of controlling the worldwide epidemic of short-sightedness - otherwise known as myopia - according to Dr Lyndon Jones who was speaking at the Global Contact Lens Forum. He explained that myopia had become a major international health issue and was recognised as such by the World Health Organisation. "It is estimated that the number of those with myopia will grow to 2.5 billion by the year 2020" stated Dr Jones. At this level of impact almost one-third of the world's population will be affected and the causes - both genetic and environmental - will not be reversible.

Today's lifestyle for children involves them spending too much time indoors in low level light on near distance vision tasks focusing on smartphone, tablet and computer screens. This contrasts with the lifestyle of 30-40 years ago when children played outdoors where light levels are up to ten times that of indoor lighting and where much of their play involved distant vision tasks. Today's children do not exercise their eyes sufficiently in well-lit environments resulting in the elongation of their eyes to fit near vision requirements. This means that light entering their eyes focuses in front of the retina rather than directly on it meaning distant objects appear blurred and this is where corrective contact lenses  can play a hugely important role.

Normally, when opticians prescribe glasses or contact lenses they do so to correct a diagnosed vision defect like short-sightedness. Now the evidence of research is that corrective contact lenses  - based on the optical science of orthokeratology or ortho-k - not only correct short-sightedness, they also prevent it from getting worse. This is especially important with children who will typically suffer continuous deterioration in their eyesight by around half a diopter every year which potentially means they enter adulthood with a high prescription. Highly myopic adults are significantly more likely to suffer serious eye health problems such as glaucoma and detached retina in later life thus highlighting the importance of early preventative action.