If we practice winter sports we have to take into account that there are You have to take care of your eyesight, because the sun can damage it. Light is broken down into three ranges of waves; ultraviolet (U.V.), visible light and infrared (I.R.). Ultraviolet rays are harmful and although most of them are absorbed by the atmosphere, its lower density in high mountains and the reflection of the snow make them dangerous. Within the U.V. There are three groups U.V.A., U.V.B. and U.V.C., the latter, the shortest waves, are the most harmful.
Visible light is, as its name indicates, the only one that we perceive and that therefore bothers us when it is intense (which does not happen with U.V. or I.R.). It is necessary to protect yourself for comfort.
Infrared rays act due to the heat they give off, and although the interior of the eye naturally absorbs I.R. Thanks to the water it contains, the cornea, however, is the one that can be damaged.
It should be noted that a cloudy sky does not stop UV rays. and since these are not visible, one may be tempted to go without glasses, since the visible light is less and not "annoying".
There are also people who are more photosensitive than others and some will "stand" being without glasses even in bright conditions, but the damage to their eyes is inevitable if they are without protection. The symptoms after a few hours without glasses are very unpleasant, with a sensation of "dirt in the eyes", stinging and constant tearing.
A lack of protection can cause ophthalmia and temporary blindness, even irreversibly damaging the cornea and conjunctiva, losing visual acuity.
In these harsh conditions, take care of your eyes. Get good glasses, when I say good I don't mean that they are fashionable and very "galactic". The important thing about glasses is their lenses and you will always find "cool" glasses with good lenses.
Look at what the labels on their crystals indicate. Do not buy glasses that do not have the manufacturer's indication and guarantee of what they filter. Good glasses must filter 100% of UV rays, remember that these rays are the most harmful. As for visible light, they should absorb between 85 and 95% depending on the conditions you are going to endure or your sensitivity to light. I.R. rays They have to be filtered at least 50%, although something more is better, up to 90%.
For high mountains must protect the eye so that too much light does not enter through the sides, either with added protections that close the gap next to the temple (the so-called glacier glasses) or with the own enveloping shape of the glasses that fits the relief of the face.
