By Nigel Little 

Contact lenses for children   worn only overnight while sleeping have been demonstrated in a recent US study to not only correct short-sightedness but also to prevent it from deteriorating further over time. This latter issue is of particular significance since research has shown that adolescent myopia (myopia is the technical term for short-sightedness) can typically worsen by around half a diopter each year resulting in children entering adulthood with high prescriptions even if they have worn glasses or daytime contact lenses throughout their childhood. The results of the SMART Study - Stabilising Myopia by Accelerated Reshaping Technique - were presented at the recent British Contact Lens Association annual conference and showed that children wearing the new overnight ortho-k corrective contact lenses showed no significant change in their prescription after three years of lens wear.

At the same time, research conducted by University of Houston College of Optometry assistant professor David Berntsen and his colleagues from The Ohio State University compared the effects of wearing and then not wearing glasses with progressive addition lenses, better known as no-line bifocals, in children who are short-sighted. The study examined 85 children from 6-11 years old over the course of two years who were selected according to their eye alignment and accuracy of focusing on near objects and who were fitted with either normal single-vision lenses or no-line bifocals to correct their nearsightedness. Berntsen's study found a small, yet statistically significant, slowing of myopia progression in children wearing the bifocals compared to those who simply wore single-vision lenses but the results were not as dramatic as those for the overnight ortho-k corrective contact lenses for children  .

Ortho-k is the abbreviated term for orthokeratology which simply refers to the way these special contact lenses for children   work. Custom-designed for each person, the lenses gently flatten the eye under the mild pressure of closed eyelids during sleep to correct the focusing distance and ensure that light enters the eye at the correct angle to reach the retina at the back of the eye. The correction lasts for over 24 hours so the child enjoys perfect natural vision all day long from when the lenses are removed each morning through until they are reinserted at night. And by this retention effect, the lenses prevent the child's short-sightedness from worsening. So whilst the Houston study has yielded interesting results about the beneficial effects of bifocal glasses for child myopes, the evidence to date supports overnight ortho-k lenses as the most effective treatment.

Check if your child is suitable for overnight ortho-k corrective contact lenses  for children.