Quick Answer
Preventing snow blindness during long treks involves wearing UV-blocking goggles, taking regular breaks to give the eyes a chance to recover, and avoiding prolonged exposure to direct sunlight on snow.
Understanding the Risks
Snow blindness, also known as photokeratitis, occurs when the cornea is exposed to intense UV radiation, usually from sunlight reflecting off snow. This condition can cause severe pain, blurred vision, and even temporary blindness. The risk is higher at high altitudes, where the atmosphere is thinner, and UV rays are more intense.
Choosing Protective Gear
Wear goggles or sunglasses with a UV-blocking coating that filters out 99-100% of both UVA and UVB rays. The American National Standards Institute recommends a minimum of 99% UV protection. Choose lenses with a dark tint to reduce glare, but avoid very light-colored or transparent lenses, which can amplify UV radiation. Consider goggles with a wide peripheral view to reduce glare from the sides.
Managing Exposure
Limit your exposure to direct sunlight on snow, especially during peak hours (10am-4pm). If you must be outside, wear your protective gear and take regular breaks (every 30-60 minutes) to give your eyes a chance to recover. In extreme conditions, consider limiting your time outdoors to early morning or late afternoon.
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