{"id":10272,"date":"2021-11-23T00:35:19","date_gmt":"2021-11-22T23:35:19","guid":{"rendered":"https:\/\/travesiapirenaica.com\/?p=10272"},"modified":"2021-11-23T23:55:02","modified_gmt":"2021-11-23T22:55:02","slug":"montana-glasses","status":"publish","type":"post","link":"https:\/\/travesiapirenaica.com\/en\/gafas-montana\/","title":{"rendered":"How to choose mountain sunglasses"},"content":{"rendered":"

*Article updated as of 23 November 2021.<\/strong><\/p>\n\n\n\n

Sunglasses are a fundamental part of our mountain equipment that sometimes we do not pay enough attention to. Sometimes we tend to see sunglasses as an accessory, as a decorative element, forgetting their main function.<\/p>\n\n\n\n

Sunglasses are a Category I Personal Protective Equipment (PPE) that protects our eyes against ultraviolet rays and excess light, but also against the impact of insects, dust, rain, branches, wind, etc.<\/p>\n\n\n\n

The danger of Ultraviolet Radiation.<\/h2>\n\n\n\n

Ultraviolet rays are part of the energy coming from the sun. They are composed of: UVA rays (long wave), UVB rays (medium wave) and UVC rays (short wave, totally absorbed by the ozone layer). Of the total UV radiation that reaches the earth's surface, 95% is UVA while 5% is UVB, the latter being more energetic and more harmful to health.<\/p>\n\n\n\n

Eyes are extremely vulnerable to this type of radiation and without adequate protection, we can suffer from minor eye discomfort to serious diseases such as photokeratitis or snow ophthalmia, erythropsia, cataracts, macular disease and even cancer.<\/p>\n\n\n\n

In the case of mountain sports, the danger is even greater. UV radiation is largely absorbed by the atmosphere, but the higher the altitude, the lower the layer that protects us. On average, it is estimated that every 1000 metres UV radiation increases by 10% to 12%, or even significantly more according to some studies in the Alpine region.<\/p>\n\n\n\n

Altitude is not the only factor to take into account. UV radiation levels also depend on the position of the sun, latitude, cloud cover, the amount of ozone in the atmosphere they pass through and terrestrial reflection. In other words, the highest levels are recorded at midday, in summer (except in the tropics), on clear days, in certain tropical areas and on surfaces that reflect a lot of UV radiation (snow: 80% and seawater: 25%).<\/p>\n\n\n\n

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Global Solar, UV index. A practical guide. WHO, WMO, UNEP. 2002, CC BY-SA 4.0 https:\/\/creativecommons.org\/licenses\/by-sa\/4.0<\/a>, via Wikimedia Commons<\/figcaption><\/figure><\/div>\n\n\n\n

In the case of Spain, the AEMET<\/strong><\/a> publishes the maximum UV radiation index prediction for each day. <\/p>\n\n\n\n

How to choose a pair of mountain sunglasses?<\/h2>\n\n\n\n

As we have already anticipated, the use of sunglasses is a matter of health and in the case of mountain sports, even more so. We will now go over the most important aspects to take into account when choosing a pair of mountain sunglasses, however, we did not want to leave the following point until the end. Our sunglasses must comply with the regulations and quality standards required by the European Union (or the American or Australian standards).<\/p>\n\n\n\n

European EC type-approval standard.<\/h3>\n\n\n\n

Don't be taken for a ride. Sunglasses are best bought from opticians and specialised shops. In the case of the European Union, all sunglasses must be accompanied by the CE marking and the following information, which you will find somewhere on the temples:<\/p>\n\n\n\n