choose sunglasses it can be more complicated than it seems. Sometimes we think that it is enough to decide if we want them in an aviator or cat eye, with a color that goes with everything or something more strident. We see them as a complement, but they are much more. It’s about a protection element for our eyes, so, in the same way that we protect our skin with sun creams, we must also choose suitable sunglasses.
For this, the first advice is usually buy them at an optician. It is true that in some clothing and accessories stores we can already find approved sunglasses, but normally, if we want to take care of our health, it is best to do so in a specific establishment, such as opticians.
On the other hand, depending on our case, we must choose sunglasses with one filter or another. Your level of protection is numbered from 0 to 4 and it depends on factors such as the activities we are going to do or our eye color. This is also a good reason to buy them in an optician, because the people who work there will be able to advise us. But, broadly speaking, what does each number mean and how can we choose the best one for us?
Our eyes protect themselves, but they can’t cope
We know that our skin has its own mechanism of defense against solar radiation. This consists of generating melanin, a pigment that absorbs these radiations, preventing them from reaching the innermost layers of the skin and damaging its genetic material. Also, precisely that melanin is responsible for us getting brown. But it has a limit above which it cannot absorb more. That’s when burns occur and, over time, spots or, in the worst case, skin cancer.
Something similar happens with the eyes, as can be read in Open your eyes!the recently published book by Conchi Lillo. They protect themselves from excess light through melanin synthesized by melanosomes within the eye. However, the same thing happens to them. When they do not cope, the light continues to enter and a photoreceptor depletion, which causes photophobia. In addition, the aging of the pigment epithelium cells is promoted, eventually causing vision problems.
And with ultraviolet radiation the same thing happens with the skin. Can cause DNA mutations which, in the long run, can lead to cancer, but also to many other eye diseases. There are plenty of reasons to choose sunglasses as something more than an accessory. But let’s see how we should do it.
Pay attention to filters when choosing your sunglasses
Sunglasses protect us from solar radiation through filters that are classified from 0 to 4 according to their darkness.
As we already know, the darker a surface is, the more light it absorbs, so higher filters absorb more solar radiation.
So, with the number 0 sunglasses with very clear lenses are classified, which only absorb from 0% to 19% of light. They are usually used indoors or for driving, even at night, but they are not useful if we are going to be on the street, directly exposed to the Sun.
With the level 1 we have glasses with filters that absorb between 20% and 56% from sunlight. These can be used outdoors, but with soft lighting, such as urban lighting.
then we have levels 2 and 3whose filters absorb from 57% to 81% and from 82% to 92% respectively. They are the most used, since they are used for medium and high light conditions, even on the beach or in the mountains. The latter applies above all to type 3, which are the most recommended for people with light-colored eyes, because they have little melanin.
Finally, we might think that level 4 is the best of all and that we should always look for that one, but the truth is that it is only used in extreme conditions. It is a filter that absorbs very high radiation, even when it is reflected from surfaces such as water or snow. For this reason, people who practice ski or water sports and want to choose sunglasses should opt for these.
Finally, it should be noted that levels 1, 2 and 3 can be used for driving, but not at night. The 4 is best left alone for those edge cases mentioned.
And what about polarized glasses?
The typical colored lenses of polarized glasses are also very useful for people who do skiing or water sports. This is because it has the ability to filter reflected light, so that glare is avoided.
However, we must be careful and not use them in any circumstance, as they also inhibit the light coming from some types of vehicle screens or even gas station indicators. It is not recommended to use them for driving.
What else should we look for?
When choosing sunglasses, we should not only look at the filters. It is also important that they are approved, because that way we will know that these filters have been correctly tested and keep what they promise. But how do we know if they are approved?
Basically, it must be reflected that they comply with the regulations. This is different in each country. In Spain it is the European Community, so the first thing to look for is its symbol, CE. The standard is EN 1836:1997 and this must also be properly marked. We should not hesitate to look for it and, if we do not see it, ask the seller. For this reason, as we have already said several times, it is best to buy them at an optician. There we can also look for cat-eye or aviator ones, with the most varied colors, but as safe as they are fashionable.