Summary:
Solar radiation is estimated to increase in intensity by 10% at every 1,000 m altitude threshold. Exposing oneself (and one's eyes) to UVB rays at these heights is particularly dangerous.
Therefore, the intensity of solar radiation is 1.5 times greater at 2,000 m and 2.5 times greater at 4,000 m (over sea level). At this level of exposure, you will require a high quality lens that offers a Category 4 protection such as the Spectron 4, Cameleon, or Zebra lens, in order to preserve eye health.
THE DANGERS OF THE SUN IN HIGH-MOUNTAIN ENVIRONMENTS
Anyone who practices high-mountain sports must be aware that they are operating in a risky environment.
While the risks linked to the mountains themselves may be obvious, those caused by exposure to the sun at high altitudes are more difficult to understand. Let me shed some light on the subject.
Exposure will vary depending on the thickness of the ozone layer in the atmosphere (which acts as a natural filter), the season and the angle of incidence of the sun's rays, which changes throughout the day.
Solar radiation is estimated to increase in intensity by 10% (between 4 and 16%) at every 1,000 m altitude threshold. Exposing oneself (and one's eyes) to UVB rays at these heights is particularly dangerous. In addition, the snow often present in the mountains reflects between 80 and 90% of solar radiation, compared with 20% on non-snowy ground.
Therefore, the intensity of solar radiation is 1.5 times greater at 2,000 m and 2.5 times greater at 4,000 m (over sea level). At this level of exposure, you will require a high quality lens that offers a Category 4 protection such as the Spectron 4, Cameleon, or Zebra lens, in order to preserve eye health.
Neglecting to use protective eyewear in high-altitude environments can lead to permanent damage to your eyes. The 4 most common eye disorders among climbers are: photokeratitis or snow blindness, erythropsia, white-out syndrome, and corneal frostbite. All of these disorders can be prevented by wearing ocular equipment suitable for the conditions.
Since 1888, Julbo sunglasses have protected our most daring adventurers on their escapades up into all of our world's greatest mountains. Used on expéditions from the jagged Antarctic landscape, to the Alps, to the 8,000 m Himalayan peaks, Julbo has honed its expertise in high-mountain sun protection and has become a benchmark brand in the field of high-altitude eyewear. Check out our mountain collection
Julbo Explorer
