Slit goggles against snow blindness: eye protection from bark or cardboard

Common mistakes

• ×Thinking of eye protection only when it hurts
• ×Going without protection when it is cloudy
• ×Cutting the slits too wide
• ×Leaving the inside light
• ×Moving fast through steep terrain with the goggles

Materials

• Birch bark (from dead, fallen wood)

  A hand-wide piece of bark from dead wood – or cardboard

  Never peel from living trees.

  Collect only with the forest owner's permission.

• Newspaper and cardboard(optional)

  Stiff cardboard instead of bark

  Flammable – keep away from candles, stoves, heaters and embers.

  Loses almost all insulation when wet.

• Knife (fixed or locking blade)

  Cut away from your body.

  Rules on carrying knives differ by region – check local rules.

• Accessory cord

  Cord or elastic for the back of the head

  Use only certified cord after training for life-safety purposes.

  The diameter must suit the main rope or friction hitches will not grip.

• Charcoal from a campfire(optional)

  To blacken the inside

  Not activated carbon: adsorption capacity is low and unknown.

  Barbecue briquettes may contain additives – do not use for water.

Prerequisites

• ·A piece of bark, cardboard, leather or dense cloth
• ·A knife

Safety

• Through the slits you see less, especially downwards and to the sides. Walk more slowly, look at the path more often and in steep terrain, near crevasses or drops only take the goggles off when standing still.
• Only take bark from dead or fallen trees. Bark peeled from living trees harms the tree and is forbidden without permission.

How it works

A narrow slit lets only a small part of the light into the eye – and hardly any of the light that comes back at an angle from below and the sides off the snow. The eye still sees almost sharply through the slit, a bit like squinting. A black inside swallows stray light and does not dazzle. This greatly reduces the UV load, even without glass.

Background

Variants

From cloth or tape

A strip of dense cloth, a scarf or two layers of tape with narrow slits also work. Tape can be stuck directly onto broken sunglasses.

Soot under the eyes

A little soot under the eyes reduces glare slightly but does not replace eye protection.

Common mistakes

• ×Thinking of eye protection only when it hurts
• ×Going without protection when it is cloudy
• ×Cutting the slits too wide
• ×Leaving the inside light
• ×Moving fast through steep terrain with the goggles

Limits and risks

• –No tested UV protection
• –Good glacier glasses are always better

Material alternatives

Derived from material properties: a substitute must have all relevant properties. Observe the notes on the substitute.

Birch bark (from dead, fallen wood)

Dry firewood (Collect only where permitted.), Tinder (Carry in waterproof packaging.), Char cloth (charred cotton) (Store dry in a tin.), Finest-grade steel wool (Store separately from batteries – fire risk.), Fatwood (resin-rich wood) (Collect only dead wood where permitted.), Stove fuel (canister, liquid fuel, alcohol) (Store fuels apart from food and in original containers or bottles intended for them.), Petroleum jelly cotton balls (Use only pure cotton.), Cooking oil or cooking fat (tallow, lard) (Never put out burning fat with water – cover it with a lid to smother it.), Tree resin (spruce, pine) (Resin is flammable and sticks to the skin when hot – melt it only slowly over low heat.)

Newspaper and cardboard

Sleeping pad, Dry leaves, grass or conifer boughs (Collect only where allowed; no protected plants. Check for ticks and insects.), Backpack, Dry spare clothing (Carry it in waterproof packaging – wet clothing barely insulates.), Wool blanket / duvet (Keep away from candles, stoves and heaters.), Insulated cool box (Keeps cold only for a limited time; without ice packs or ice it is not a fridge.), Sleeping bag (Do not store compressed long-term; do not pack away damp.), Insulated cooking box (hay box, thermal cooker) (Never put open flame or embers inside – only the hot, closed pot.), Long-stemmed thatch (reed, grass, rushes) (Extremely flammable – no open fire and no sparks nearby.), Pot insulation (pot cosy, beanie or fleece jacket) (Only around a pot that is no longer on the stove – fabric catches fire at the flame.)

Accessory cord

Rope (Never use unknown or damaged rope for life-safety purposes.), Paracord (Not a climbing or safety rope.), Thin twine (Low breaking strength – light loads only.), Webbing (tubular webbing) (Inspect knotted webbing before every use.), Jute or sisal twine (bought) (Low strength, absorbs water and rots – light loads and practice only.), Tree straps (Load only within the manufacturer's limits.), Monofilament fishing line (Never leave scraps of line behind: birds and other animals get tangled in them and die slowly. Wind up scraps and take them with you.), Thin, soft wire (brass or galvanised steel) (Wire ends are sharp – protect eyes and fingers when bending), Tow rope or tow strap (Attach only to the towing eyes provided by the manufacturer; never stand next to it under load.)

Charcoal from a campfire

Cotton cloth / T-shirt (Removes coarse particles only – no disinfection.), Coffee filter (Does not disinfect.), Gravel

Results come exclusively from structured entries. No improvised instructions are generated.