Sunlight and vision: why UV rays are dangerous for your eyes

The sun is essential to life, but it also poses a real risk to the health of your eyes.
Some of the radiation it emits is visible—this is light—while other types are invisible and can be particularly harmful, especially ultraviolet (UV) rays.

Solar radiation travels through space and then the Earth's atmosphere before reaching us. Some of it is filtered, particularly by the ozone layer, but not all of it.

There are three types of ultraviolet rays:

• UVC: the most dangerous, fortunately blocked by the ozone layer.

• UVB: partially filtered, but responsible for burns and lesions.

• UVA: the most prevalent, they penetrate deep into the eye tissue.

UVA and UVB rays reach the eye directly and are absorbed by the cornea, the lens, and sometimes even the retina.

The cornea and lens act as natural filters, but this protection is limited.
Over time, repeated exposure to UV rays has a cumulative effect, which can cause:

• premature aging of the eye,

• lesions of the lens,

• an increased risk of long-term eye diseases.

The risks exist from sunrise onwards and increase significantly between 11 a.m. and 3 p.m.
They are accentuated by reflective surfaces:

• snow: up to 80% reflection,

• water: approximately 20%,

• sand: approximately 10%.

Children's eyes are much more sensitive to UV rays than those of adults.

• Before the age of 10 to 12, the lens of the eye does not yet filter UV rays effectively.

• In babies, almost all UVA and UVB rays reach the retina.

• At around age 10, approximately 60% of UVA rays and 25% of UVB rays still reach the retina.

Children with light-colored eyes and fair skin are even more vulnerable. This is why it is so important to protect their eyes from an early age.

It is better not to wear sunglasses than to wear ineffective ones.

Why?
Dark lenses without UV protection cause the pupil to dilate, allowing even more harmful UV rays to enter the eye.

The tint reduces glare, but only the glass material protects against UV rays. Clear glass can filter out 100% of UV rays, while very dark glass may not provide any protection at all.

Glasses must cover the eyes properly:

• no space on the sides,

• nor above,

• nor below.

Frames that are too small or purely aesthetic allow UV rays to pass through the sides.

Some lenses have special coatings that filter out 100% of UVA and UVB rays.
This protection is essential:

• for children,

• for sensitive eyes,

• in the mountains, at the seaside, or during prolonged exposure.

Contact lenses can filter UV rays, but they only cover part of the eye. The eyelids and the "white of the eye" remain exposed, with risks of burns or ophthalmia.

Contact lenses are therefore never a substitute for a good pair of sunglasses.

At Optique Moitzheim, we recommend sunglasses and lenses that offer optimal UV protection, tailored to your vision, lifestyle, and the whole family.

Come visit us in store for personalized advice.