This article was originally published here.

In general, a child's eye is not developed enough to cope with the sun's UV rays.

The extreme sensitivity of children's eyes to the sun's rays can be explained by two factors:

1. 1st Factor : Lens Development In Children

What is the lens?

The lens is the part of the eye that allows it to adapt to light. Outdoors, especially in sunny weather, it lets you filter out the various UV rays.

The lens acts as a natural filter of the sun's rays, but it does not become fully operational until adulthood. Its role as a protective filter only begins at the age of 12.

Before that age, children are very sensitive to UV rays because the lens lets through more than 75% of UV rays.

> From 0 to 1 years: only 10% of UV rays are filtered, which means that 90% of UV rays reach your child's retina.

> From 1 to 12 years: only 40% of UV rays are filtered, 60% of UV rays still reach the retina.

> From 12 years: the amount of UV rays that pass through gradually decreases due to the lens becoming opaque and beginning to effectively play its role as a natural filter of UV rays.

Further information on "the ages of eyesight" is available on the ASNAV website (the French national association for improving vision).

To learn all about how the lens works, check out our article on the eye and the lens.
2. 2nd Factor : Blinking

Have you ever caught your child looking directly at sunlight without blinking?

Without seeming to experience any discomfort?

For little ones, blinking is not yet fully operational. The reflex that enables them to close their eyes to protect themselves from bright light is not yet fully developed. They are therefore able to withstand intense light without blinking.

This ability to look at the sun for long periods of time without any pain or discomfort thus increases the impact of the sun's rays on their vision.
3. What Are The Risks For Your Children'S Eyes?

There are many risks:

> Squinting

> Watery eyes

> Intolerance to light

> Inadvertent eye rubbing

> Early onset of cataracts

> Macular degeneration (AMD)

Some symptoms can be immediate and others appear gradually with age. Just like for skin, we have a "vision quota": we all have a quantity of UV rays that our eye can absorb and each UV ray that reaches the eye consumes this quota. The younger the child, the more UV rays are dangerous. It is therefore important to wear sunglasses from an early age.

Good to know: Sunglasses should not be worn only when your child is exposed to direct sunlight! Even if your child is protected by a parasol on the beach or in the snow, the reflection of sand, water and snow emits a quantity of UV from below that reaches the eye.

Added to this is a second constraint: children, because of their young age, are not aware of these risks and do not always want to wear their sunglasses: this does not make things any easier! That is why it is important for your child's sunglasses to be comfortable and well adapted to the size of their face so that they are not bothered by them.
4. How To Choose Sunglasses For Your Child ?

Now you know why it is essential to properly protect your children from the sun's rays by choosing suitable sunglasses for them and ensuring that they wear them as often as possible.

Particularly between 11am and 3pm, where the sun's rays are the most dangerous. All the more so by the sea, in the mountains, and even under a sun umbrella!

Also take a look at our advice guides on how to choose the right children's sunglasses.