Myopia (short-sightedness) has become much more common worldwide in recent years and in the UK between 20- 40% of the population are now myopic. The reasons for this are not yet fully understood but we do know that children with two myopic parents are more at risk. Myopic eyes tend to be longer in length and research has shown that this excessive growth may be a response to the visual environment, namely excessive close work (reading and screen use).
Research has also shown that children who become myopic tend to spend significantly less time outdoors than children without myopia and that spending upwards of 10-14 hours/week outdoors is protective against myopia.
Being myopic is not simply inconvenient, it also significantly increases the lifetime risk of developing serious eye conditions such as retinal detachment, myopic maculopathy, cataract, and glaucoma. The risk goes up with the level of myopia so anything we can do to reduce the level of progression of the short sight is highly beneficial.
The onset of myopia is typically in the school years, with progression by variable amounts as the child grows. One can never be certain how much an individual child would have progressed without intervention but the research is clear that the following strategies have shown an effective slowing down of progression by up to 50%. The effect for a particular child may be more or less than this.
Ortho K contact lenses temporarily reshape the cornea so that light focuses on the retina, leading to clearer vision. These contact lenses are worn overnight while asleep and the effect lasts 24 hours or more so that the child is free of spectacles or contact lenses during waking hours. This strategy offers a significant reduction in myopia progression of approximately 50%, which is thought to be due to myopia-preventing peripheral blur being created by the ortho K lenses. It also has the advantage that the contact lenses are used only in the home environment so the contact lens wear can be supervised by parents.
Multi-focal and dual-focus soft contact lenses can also be fitted with similar results to ortho K lenses. There is a “myopia control” daily disposable soft contact lens for children.
Bifocal and multifocal spectacle lenses can offer a modest reduction in myopia progression due to a reduction in myopia inducing blur, but are significantly less effective than ortho K or dual-focus soft contact lenses.
For the future
Atropine drops in very low concentration (0.01%) have been shown to be very effective in preventing myopia development/progression, however, the mechanism by which it does this remains unknown. Atropine 0.01% is not currently commercially available in the UK, but as research advances in this field, it may become available to suitably qualified optometrists in the future.
Under-correction of the short-sighted with spectacles
It used to be thought by some people that wearing glasses of full strength made the sight get worse, but it is now known that the reverse is the case – under-correction actually accelerates eye growth. We believe that keeping up with regular tests and spectacle and contact lens updates will help with this.
So to summarise, current evidence-based guidance would be to keep up with regular eye tests and prescription changes whilst also trying to ensure your child spends as much time outdoors as possible. We recommend considering one of the active myopia-control contact lens options, as they offer children many benefits of freedom from glasses as well as benefiting the long-term health of their eyes.