Snow blindness is a painful condition caused by exposure of unprotected eyes to sunlight reflected from snow. This is especially a problem at high altitude and polar regions.
The problem is also related to the condition arc eye sometimes experienced by welders.
Some guidelines to use when choosing a good trekking/mountaineering pair of sunglasses:
- 99-100% UV absorption
- Polycarbonate or CR-39 lens (lighter, more comfortable than glass)
- 5-10% visible light transmittance
- Large lenses that fit close to the face
- Wraparound or side-shielded to prevent incidental light exposure
See also
