Children with short-sightedness, called myopia, tend to show regular progression or worsening of their vision over time. However there are ways to slow down this worsening, called myopia control or myopia management. Typically, when a child first becomes myopic, their first vision correction will be spectacles (glasses). Types of spectacle lenses which may be prescribed to a myopic child include:
- Single Vision – these just correct for the long distance vision problem
- Bifocal lenses – these have the visible line in the middle of the lens, with the top half correcting for long distance vision and the bottom half correcting for reading vision
- Progressive addition lenses (PALs) – these can be thought of like a bifocal, but without the line. They feature a continuous blend of power from the top of the lens (long distance vision) down to the bottom of the lens for reading. Many adults over the age of 45 wear these, and kids can wear them too.
- Myopia control specific lens designs – these include peripheral plus and multisegment designs, and you’ll learn more about these below.
When your child is myopic, we have to firstly think about correcting their blurred distance vision, which we can do with spectacles or contact lenses. So far, the vast amount of myopia control research indicates that myopia controlling contact lenses offer better effectiveness for slowing down the worsening of childhood myopia. You can read more about contact lens options and the safety of contact lenses in children via the links. However your child, or even you, may not yet be ready for contact lenses! Hence it’s important to understand the spectacle lens options. And while it’s not yet readily available, there is one type of special myopia control spectacle lens design which is showing similar results for myopia control to the contact lens options – more on that later!
Let’s take a look at each of these spectacle lens options in more detail.
Single vision spectacle lenses
These are the standard type of spectacle lens typically prescribed for vision problems in children and adults, where only one focussing distance (far or close) needs support with glasses.
Single vision spectacles DO NOTHING to help slow down the progression or worsening of vision which is typical in children with myopia. They SHOULD NOT be the first choice for your myopic child.
In fact, numerous research studies have used single vision spectacle lenses in their control groups – meaning the group which gets no intervention compared to a treatment group wearing one of the other types of spectacle lens or contact lens designs which are shown to control myopia. If your child is prescribed single vision lenses for myopia, you should ask your eye care practitioner if they can do better!
What’s even worse than single vision lenses? Single vision lenses which are underpowered for long distance. This is still a common practice in Asian countries – where parents and even eye care practitioners can feel that a child shouldn’t be given their full prescription, under the mistaken belief that stronger glasses will make their eyes worse. However the opposite is true! It’s been shown that underpowered glasses actually speed up progression (worsening) of childhood myopia. (research link) This is the last thing we want!
Occasionally, your child’s eye care practitioner may have a good reason to prescribe single vision distance corrected spectacles for your myopic child – this can be due to eye muscle teaming disorders, for example; or as a back up to better options like contact lenses. They may also be prescribed to correct vision when atropine eye drops are chosen as the myopia control treatment. In any case, you should understand why single vision, distance correcting spectacle lenses have been prescribed for your child – make sure to ask your eye care practitioner why, and if there’s any better options if your child’s vision does show progression or worsening when wearing these lenses.
Bifocal spectacle lenses
Bifocal spectacle lenses are like two lenses stuck together – the top half corrects for long distance vision and the bottom half for reading and up close vision. Bifocals are frequently prescribed to children with eye muscle teaming and coordination problems. They have also been shown to slow down myopia progression in children by about a third in one three year study. (research link) The main drawback of bifocal spectacles is the appearance of the line in the middle of the lens.
Progressive addition lenses
Progressive addition (PAL) lenses, also known as multifocal spectacle lenses, have a graded power from the long distance correction at the top to the full reading power at the bottom of the lens. They can be thought of like a bifocal but without the visible line in the middle. Children may be prescribed PAL lenses for eye muscle coordination problems and to support their reading vision; many adults over 45 wear PALs to correct both their far and close vision in the same pair of spectacles, to avoid having to switch between two pairs or take reading glasses on and off.
PALs prescribed to any myopic child show very minimal effects for myopia control, however for children with specific eye muscle teaming problems, they have been shown to slow myopia progression by about a third.
Myopia control specific lens designs
Special spectacle lens designs have been developed by the optical industry to attempt to control childhood myopia progression more effectively than the typical bifocal and progressive designs. These include the peripheral plus design, marketed by Zeiss as MyoVision, which showed a 20% myopia control effect in a one year study, for children aged 6-12 years with a family history of myopia. This lens is available in many countries. (research link)
The most effective spectacle lens design for myopia control, according to research, is the Defocus Incorporated Multisegment Spectacle (DIMS) lens, which has shown a 62% myopia control effect in children aged 8-13 years, over a two year study. This is being marketed by Hoya as Miyosmart and is now available in some Asian countries. (research link)
Which is best?
Your eye care practitioner will be the best guide of which option is most suitable for your child, as it can depend on their level of myopia, eye muscle coordination, age and more. The newer myopia control specific lens designs are also not available in all countries. If your eye care practitioner doesn’t feel that spectacle lens options are the best option to control your child’s myopia, they may recommend contact lens options or atropine eye drops. It’s important for you to also understand the influence of your child’s visual environment – outdoor time and screen time – on successfully managing their myopia.