My child is going to 1st grade and doesn't know the colours; what should I do?

It's not always easy for young children to identify colours and it's best to have a visual screening before they start school. The ophthalmologist Miguel Raimundo explains why:

Our retina, which is the photosensitive layer of the eye and converts light into electrical pulses, distinguishes two types of photoreceptors. The first are rods, which are specialised cells for detecting moving light, and the second are cones, which are used for detail vision but also for colour. We have three types of cones: one more sensitive to red, one to green and one to blue. And, basically, our brain combines the information from these three cones and allows us to distinguish colour.

Now, if there is a mutation in one of these cones, and by far the most frequent ones are those affecting the green cone, this leads to the clinical situation we call red/green colour blindness, which appears in about 5% to 8% of men and 0.5% of women. This leads, if it doesn't work at all, to complete colour blindness or, if they are partial mutations, to partial colour blindness. And what happens to these people? In practice, and with varying severity, greens and reds are easily confused and come to be perceived as if they were low saturated browns.

What is the good thing? It is that the vision is otherwise completely normal, and does not progress or worsen over time. Often the diagnosis is made almost accidentally. In children, often the youngest, there is some difficulty in learning colours and they easily change these more ambiguous colours, at least for them. Often, in more practical things, they change the colours of their socks. In a child where the only difficulty in seeing is this, there is no need to worry.

As colour vision is only one aspect of vision, and in order to ensure that this and other aspects are completely normal, it is always important to have a routine check-up with an eye specialist. Immediately before she enters school to ensure that she enters in the best possible condition in terms of healthy vision.

Tomorrow we talk about the care of virtual books and interactive whiteboards.

With the support of the Portuguese Society of Ophthalmology.