Strabismus : the child squints.
What is it ?
It is a lack of coordination between the two eyes. Depending on the cases, the deviation is more or less important, periodic or permanent. It can affect one eye or both. Its cause : an eyesight disorder or a defect in one of the muscles that make the eyes move. Its consequence : the child can see double.To compensate, they use spontaneously their dominant eye in order to neutralise one of the two images received by their eyes.
Be careful : non-corrected strabismus can provoke amblyopia. This symptom can sometimes only be seen when the child is tired but you should have them checked anyway.
What should be done ?
Physiotherapy, surgery or wearing glasses.
Amblyopia : one of the eyes is "lazy".
What is it ?
It is an eyesight disorder provoked by non-corrected strabismus or ametropia in children older than 3 months. Also called "a lazy eye", this disorder affects 5 to 6 % of babies. It is the result of a long-sighted or squinting eye making poor quality images. The brain then selects the better quality images produced by the eye which sees correctly. The other does not work any longer: it becomes lazy ! Up to 2 years old, amblyopia can be entirely corrected. But after 6 years old it is often too late. This is the reason why it is best to have exams very early in order to detect and treat the disorder. The earlier the treatment, the bigger the chances are to recover.
Parents can detect potential amblyopia by hiding each of the baby’s eyes for 15 to 20 seconds. As the test is done several times, if the child does not protest or protests very little, there is no need to worry. If the child cries or gets unusually nervous when one eye is hidden, it can mean that the eye which is not hidden sees blurred. In this case, it is better to consult an optometrist as soon as possible.
What should be done ?
Physiotherapy most often consists in temporarily "hiding" the good eye to force the lazy eye into action. The occlusion will be set for 20 to 30 minutes a day for a 6 month-old baby, and longer for an older child. In some cases wearing adapted glasses or contact lenses is advised.
Disorders in colour vision :
What is it ?
This eyesight disorder consists of a bad perception of primary colours: red, green or blue depending on the case. It is often hereditary and mainly affects boys.
For more details : Disorders in the perception of colours