Have you noticed your child squinting their eyes to read signs or watch TV? Early signs of myopia or shortsightedness should be investigated promptly.
Read on to learn what to look for and why it is important to pick up myopia early.
Why is my child squinting?
If your child is seeing well up close, but squinting to see in the distance, chances are they are shortsighted – a condition also known as myopia.
In a shortsighted eye, light is focused in front of the retina, so distant images appear blurred.
So where does squinting come in?
Optically, the eye can be compared to a camera. The cornea is like the lens of a camera; the retina is like the film and so on.
The iris (or coloured part) of our eye is like the aperture on a camera. It can vary the amount of light coming through the pupil. The smaller the pupil, the less light comes in but the sharper the focus. The larger the pupil, the more light gets in but the poorer the focus.
A small pupil, like a small aperture on a camera will give a sharper image.
Squinting the eyes allows the eyelids to cover over part of the pupil, effectively making it smaller. The same effect can be achieved by looking though a pinhole.
Even a shortsighted eye will see quite well through a pinhole, and squinting is the eye’s best method of creating a pinhole effect. Your child won’t know this of course; they’ll just notice that by squinting their eyes, they can suddenly see a lot clearer.
Other signs your child may have myopia
The following are other clues that your child may be becoming shortsighted:
- Sitting very close to the TV
- Falling behind or acting up in class (because they can’t see the board)
- Headaches, eyestrain or fatigue, especially after visual tasks
Myopia just means glasses, right?
Wrong. In myopia, the eyeball is not normal. It becomes elongated, or stretched out as the myopia gets worse (or progresses). All the structures of the eye (such as the retina) also become stretched and thinned out.
For low degrees of myopia, this effect is mild. But even then is associated with higher risks of certain eye diseases such as macular disease, glaucoma and cataract. As the myopia increases, the risk of developing an eye disease increases greatly. The table below summarises the increased risk of developing eye disease if you are shortsighted:
|Amount of Myopia||Retinal Detachment Risk||Glaucoma Risk||Cataract Risk||Macula Disease|
|-1.00 to -3.00||3.1x higher risk||4x higher risk||2.1x higher risk||2.2x higher risk|
|-3.00 to -6.00||9x higher risk||4x higher risk||3.1x higher risk||10-40x higher risk|
|-6.00 to -9.00||21.5x higher risk||4x higher risk||5.5x higher risk||127x higher risk|
|-9.00 or greater||44.2x higher risk||4x higher risk||5.5x higher risk||349x higher risk|
It is obvious from this chart that there is a big difference between low-to-moderate degrees of myopia (-1 to -3) compared to higher amounts (over -6).
So there is a lot to be gained from preventing the progression of myopia. This is where myopia control comes in.
What are the best ways to control myopia?
Glasses and contact lenses correct myopia but do nothing to slow or halt its progress.
Myopia control is different. It uses various methods to stop the eyes from becoming shortsighted. Sometimes it stops completely. Other times it slows down.
Most shortsighted people do not continue to get progressively worse through their lives. Their eyes usually stabilise by the early 20s. If you can keep the glasses prescription to a minimum until this age, the future will be a lot rosier; there are more options to correct the vision as well as lower risk of eye disease.
Nip it in the bud
The following methods of myopia control are currently used with varying degrees of success.
|Treatment||Effect on slowing down myopia|
|Orthokeratology (ortho-k) lenses||30 – 56%|
|Multifocal soft contact lenses||25 – 72%|
|Atropine eye drops||34 – 96%|
|Executive Bifocal glasses||39 – 51%|
|Progressive glasses||11 – 33%|
One moderately-effective method is bifocal or multifocal glasses. These are worn by children and allow a comfortable near focus for reading while keeping distance vision clear.
Contact lenses for myopia control may be orthokeratology or multifocal contact lenses. These tend to be better at slowing the progression of myopia, but they need a greater commitment from the child (and parents). Lenses need to be fitted, cleaned, inserted and removed.
Atropine eye drops are an alternative to glasses or contact lenses, or can be used in addition to one of these other options. Eyedrops compounded from very dilute atropine (usually 0.01%) are used in the child or teenager’s eyes every night for a number of years.
The ATOM studies looked at the results of this method of myopia control and found it to be effective and having very few side effects (in the 0.01% concentration).