Should kids go out to wear sunglasses?
In the previous article, we have talked about What is the basic knowledge of sunglasses？ But most sunglasses are for adults, so should kids wear sunglasses when they go out? And why should kids need to wear sunglasses？
When we are outdoors, we will do a good job of sun protection, and many people will buy a pair of sunglasses to block the dazzling sun. Qualified sunglasses can filter out most of the ultraviolet rays and blue light, which can protect our eyes well. When people are exposed to harsh sunlight, the lens in the eye filters some of the UV rays. When the ultraviolet rays are too strong, people will unconsciously squint their eyes and reduce the incidence of ultraviolet rays by narrowing the pupils. The baby's eyes are more fragile. The American Academy of Pediatrics recommends that the baby wear sunglasses. Therefore, the baby's sun protection work must be armed to the eyes. Wear sunglasses if you can. Because the lens of children's eyes is much more transparent than adults, and its ability to resist ultraviolet rays is relatively weak, if no protective measures are taken, the damage to the baby's eyes is still relatively large.
Sunlight mainly includes infrared, visible, and ultraviolet. The visual development of infants and young children requires the stimulation of visible light, not high-energy ultraviolet light. Human eyes can automatically filter UV light. Because the cornea only allows light with wavelengths above 295nm to enter the eye and absorb UVA, the lens can absorb the energy of light with wavelengths below 400nm and absorb UVB. Even so, 1% of ultraviolet rays still reach the retina, which is enough to induce the disease in susceptible people with age-related macular degeneration.
UV damage is invisible, adults can filter most of it, children can't. Infants have higher lens transparency than adults, which means more UV rays penetrate! Lens transparency: 95% at birth, 80% at 6 months, 75% at 8 years old, 20% at 25 years old, so the lens actually plays the role of intraocular sunglasses. If you don't give your child sunglasses, your child's lens is forced to absorb more UV rays.
Excessive UV exposure in childhood and youth manifests itself in old age due to the cumulative effect of UV rays on the eyes. Pterygium is a mild risk, senile cataract is a moderate risk, and age-related macular degeneration is a severe risk, which is a blinding eye disease that affects about 7.4% of Asians.No one can guarantee that your child will not belong to this 7.4% susceptible group. Sunglasses are the best precaution, so be sure to wear them!
Sunglasses block UV rays. Sunglasses come in different colors, with 0-4 shades, and have different filtering rates for visible light, not completely blocking visible light. We most commonly use 3 shades, mostly amber or brown, 9-18% of visible light will pass through sunglasses, mainly worn in strong light (summer noon and seaside). If it really wants to affect the visual development of children, it is necessary to completely block the light， for example, ptosis and cataracts. Take children with amblyopia as an example, completely covering the "healthy eye" for 12 hours a day, at least 6-12 weeks, will gradually affect the vision of the "healthy eye".
Therefore, wearing sunglasses for your baby will not affect vision development. What really matters is how to choose sunglasses that meet the standards and are suitable for your baby.
How to choose the right sunglasses for your baby?
Although cheap sunglasses can also filter UV rays, we still need to pay attention to the paint of the frame. In 2014, the U.S. Consumer Product Safety Commission announced a recall of children's sunglasses made in China due to excessive lead content in the paint. In addition, the rationality of the design of sunglasses for babies is also critical!
1. Lenses must be able to filter 100% of UV rays: look for labels with 100% UV absorption or UV4002. The lens is large enough: it covers the eyes, and it is also dustproof in winter, and the wrap-around type is the best, which can filter the reflected light from the temporal side.
2. The lens is large enough: it covers the eyes, and it is also dustproof in winter, and the wrap-around type is the best, which can filter the reflected light from the temporal side.
3. Adjustable rubber elastic straps attached to the temples: keep the glasses behind the head instead of supporting them by the ears. Hang it around your neck when not wearing it to prevent it from being lost. 
Attention： Eyeglasses with elastic straps must be worn under adult supervision, and small babies and young children may be wrapped around their necks and suffocate.
4. Plexiglas: Lighter and more stress-resistant than standard plastic lenses.
5. The mirrored ring is not easy to break: children must avoid breaking the mirror ring and inserting it into the eyeball, which is too dangerous!
6. There is a spring hinge between the temple and the pile head： It will not pinch the baby, the outward expansion angle is larger, and there is a rebound effect, which reduces damage when landing.
In addition, there are strict industry standards for children's sunglasses abroad: Australia AS/NZS 1067:2003, US ANSI Z80.3-2001, Europe EN 1836:2005. Sunglasses are also labeled with 100% UV absorption or UV400.
As early as 2015, the World Health Organization (WHO) published an article "Ultraviolet Radiation and Human Health", the article clearly pointed out that the ultraviolet rays in the sun are very harmful to the eyes. Not only can damage the retina and macula, but also cause a variety of eye diseases, leading to vision loss.
Unlike adults, children are exposed to the sun for three times longer than adults and are naturally more damaged by ultraviolet rays than adults. Therefore, children should wear sunglasses not only in summer but also on cloudy days and after snow in winter.
Should children wear sunglasses? And at what age can a child wear sunglasses? How do you choose sunglasses for your child? We'll explain that in the next article. Thank you for reading.
