How does your child react?
Since babies are unable to clearly signal what they see, objective methods must be used to assess their visual potential. It is important to assess their reaction to monocular occlusion (when one eye is covered) which can show asymmetry of vision (amblyopia) if the baby starts to cry while their “good eye” is hidden. If in doubt, some devices can measure refraction and help judge the need for optical correction. Another method consists, using a monocular, in directing the baby’s gaze in the direction of patterns whose resolution gradually increases to quantify vision indirectly (preferential gaze test). When you have a family history of eye diseases, do not hesitate to inform your paediatrician who will then assess the need for a complete eye screening examination with an ophthalmologist to provide your child with the best possible care.
On older children
On older child, several small, simple tests can be carried out. The most important thing is to compare the vision of both eyes, covering one eye and then the other: are the images of small shapes as sharp with each eye at a distance? Up close? For this last test, you can use the pictures below, making sure the child can see such small shapes with each eye. This test does not make it possible to quantify the vision (this will be carried out by the paediatrician or the ophthalmologist), but just to verify that both eyes see equally well and that there is no significant visual asymmetry (amblyopia). Talk to your paediatrician if you suspect visual asymmetry. A screening ophthalmologic examination is often recommended.