In terms of vision andvisual acuity, these are not perfect from the moment a child sees the light of day for the first time. The child goes through several phases, and we're going to find out about them today.

First of all, we'll define a number of terms that we'll use to quantify children's vision.

Visual field: This is the total area in which visual perception is possible when looking straight ahead. Expressed in degrees, the visual field is small at birth and increases as the child grows. To enable young children to detect movement, we recommend that they follow slow movements with their eyes during their first weeks.

Visual acuity: This term is often used in optics, and refers to the quality of a person's vision. It improves over the months, enabling the child to see in greater detail. To fully understand visual acuity, we need to imagine that the higher it is, the better the individual's ability to perceive the details of an object (for example, the very small lines during an eye examination at the ophthalmologist's). Nevertheless, we are not all equal, and some people, even with optimal optical correction, will retain low to average acuity due to other factors, which you can find in our our article on low vision.

Color vision: At birth, contrary to what you might think, a child sees only in black and white. It's only later, and step by step, that he or she begins to develop color vision (with the development of cones on the retina, which you can find out more about in our our article on color blindness).

We'll now take a look at several stages in a young child's life, to see at what pace his various visual faculties develop.

- At the age of one month, the child's visual field is still only 55°, his acuity is 1/30 and he still sees in black and white, making it difficult for him to perceive the world around him.

- At 3 months, he begins to perceive shades of red. His acuity and field of vision improve slightly.

- At 9 months, he can see all bright colors, his field of vision is almost complete (150°) and his visual acuity has risen to 3/10.

- From the age of 1, his field of vision is complete, i.e. 180°, and he perceives all the nuances of color around him. However, visual acuity is only 4/10

- It's onlyfrom the age of 6 that children reach a visual acuity of 10/10, which is why we teach them to read from this age onwards, in the best possible conditions.

It's also highly recommended to carry out vision screening tests as soon as children enter elementary school, to detect any visual disorders, such as the ones below:

Strabismus: This is a defect in the parallelism of the axes of vision. It's very important to intervene before the age of 6 if your child suffers from strabismus, by consulting an orthoptist, who will find the most appropriate solution.

Amblyopia: A visual defect in one or both eyes. To correct this defect, the eye with the best acuity needs to be masked, to "force" the other eye to work.

Myopia, astigmatism and hyperopia are other eye disorders, but can be corrected simply by wearing glasses.

NB: Hypermetropia can lead to strabismus if left uncorrected, as the child uses accommodation to see clearly, causing the ocular axes to converge. For further information, please refer to our article on eye defects.