At the beginning of the spring season, weather expectations are usually quite high. We hope for some warmth at least, knowing we cannot ask for the heat of high summer just yet. While the season’s sun rays don’t make us sweat, one should however not underestimate the UV radiation that goes along with them (especially after a long winter).
But what is UV radiation, actually?
The letters “UV” stand for ultraviolet and mean that part of radiation that has the highest energy. It is not visible to the human eye and (in contrast to the warmth) not perceptible with any of the other sensory organs. UV radiation can be divided into three categories according to specific physical and biological characteristics:
UVA radiation is the section with the longer wavelength (400 – 315 nanometres). UVB radiation has a medium wavelength (315 – 280 nanometres), and accordingly it is also called “medium-wave UV”. UVC radiation is the section with the shortest waves – and hence the most energetic (wavelength 280 – 100 nanometres).
Generally, we can say that the more energetic the radiation, the more health detrimental it is to us. However, UVC radiation does not reach the surface of the Earth since it gets filtered out completely at higher levels of the atmosphere. Lucky us! UVB radiation also gets filtered out, however the proportion depends on the protective ozone layer. If it is damaged, more UVB gets through. At present, the amount of UVB radiation that we are exposed to is at about 8 to 10 percent.
UVA radiation reaches the Earth largely unobstructed, which is a real danger to us. The closer our vicinity to the equator the stronger the UV radiation, which is why, although it is essential to protect yourself from the sun in our Northern European summer, it’s especially vital when you’re in Southern regions. But also bright and shiny winter landscapes can give us the eye and simultaneously harm our eyes… For snow reflects radiation just like water or sand does, which increases the negative effects. Additionally, the radiation is intensified by the altitude.
And what’s the impact of UV radiation?
Natural as well as artificial UV radiation impacts our body, in particular our skin and eyes. Just how deeply the radiation penetrates skin and eyes depends on the wavelength. UVA with the longer wavelength of 315 – 400 nanometres goes deeper than UVB radiation with the shorter wavelength of 280 – 315 nanometres.
The effect on the skin cells and on the cells of the eyes varies. The most profound change is a damage of genetic material, i.e. the DNA. Even a small amount of UV radiation destroys the genetic substance of skin cells – long before a sunburn emerges. Usually the damage of genetic material gets reversed by repair systems within the cell. But these get overloaded with intense and long lasting exposure.
Damage that has not been sufficiently repaired can lead to lasting changes of the genetic material (mutations), which increase the risk of skin cancer. Hence in 2009, the International Agency for Research on Cancer (IARC) has rated UV radiation of the sun, as well as the artificial UV radiation emitted in sunbeds, the highest risk group 1 “carcinogenic to humans”.
Concerning the eyes, we can discriminate between acute and chronic effects. The first ones, arising immediately or within minutes, hours, or days after UV exposure include:
- Keratitis (or photokeratitis)
- Pink eye (photoconjunctivitis)
- Photochemical retinal damages
Long-term there is also the risk of cataract (lens opacities).
How can I protect my eyes?
Sunglasses offer effective protection. They are indispensable not just as a glare shield but they also prevent UV radiation from penetrating the eye. However, unfortunately not all sunglasses provide sufficient UV protection. You can check this with the help of the labelling. Tests have shown that the labelling “UV400” stands for reliable protection. It means that the sunglasses filter out all UV radiation up to 400 nanometres. So, when shopping for sunglasses, you should make sure that this is provided, or, to be on the safe side, purchase your sunglasses only from certified opticians such as Edel-Optics.
Should you need prescription sunglasses, it is advisable to make sure that the filter effect of up to 400 nanometres is still given after the lenses have been fitted to your prescription.
Concerning the choice of lens colour, the general rule of thumb is that brown, green and grey hues are best for sharp vision. Blue and red coloured lenses, on the other hand, tend to be detrimental to contrast rendition.
The best glare protection is given with sunglasses that have broad temples. These provide protection from the sides and prevent dispersed UV radiation from reaching your eyes. A prime example for this is the Versace VE2163.
In case this model is not of your liking, please feel free to look for alternatives. With a product range of almost 30,000 sunglasses we offer a vast choice of ways to protect your eyes and looking great at the same time 😉