What causes short-sightedness?
Short-sightedness usually occurs when the eyes grow slightly too long.
This means that light doesn't focus on the light-sensitive tissue (retina) at the back of the eye properly.
Instead, the light rays focus just in front of the retina, resulting in distant objects appearing blurred.
It's not clear exactly why this happens, but it often runs in families and has been linked to focusing on nearby objects, such as books and computers, for long periods during childhood.
Ensuring your child regularly spends time playing outside may help to reduce their risk of becoming short-sighted.
Read more about the causes of short-sightedness.