An anti-fog sheet structure includes: a substrate made of polycarbonate, a first synthetic polymer film formed on a first main surface side of the substrate, and a second synthetic polymer film formed on a second main surface side, wherein the first synthetic polymer film has, on its surface, a plurality of first bumps having an equivalent circular area diameter Dp1 in the range of more than 50 nm and less than 500 nm, the second synthetic polymer film has, on its surface, a plurality of second bumps having an equivalent circular area diameter Dp2 in the range of more than 20 nm and less than 500 nm, and the first synthetic polymer film is formed from a cured product of a photocurable resin containing 30 mass % or more of ethoxylated pentaerythritol tetraacrylate.

This sheet attachment structure includes a shield provided with a through hole, a sheet member that covers the inner surface of the shield, and a retaining part for attaching the sheet member to the shield. The sheet member includes a recessed section that engages with the retaining part, and a first electrode and a second electrode that are arranged side by side in the thickness direction of the sheet member. The retaining part includes a first shaft part that fits with the through hole, a first terminal that makes contact with the first electrode, a second terminal that makes contact with the second electrode, and a second shaft part that engages with the recessed section. The first terminal is electrically connected to a first external wiring via the through hole, and the second terminal is electrically connected to a second external wiring via the through hole.

A head-worn air pump is provided in a housing, which directs a stream of air to the goggles between the user and the interior surface of the goggles. The housing is mounted to the user's head independently of the goggles. One or more flexible tubes or hoses can be attached to a manifold or plenum at the housing that receives air under pressure from the pump, and extend from the rear of the head to one or both sides of the goggles. The air can be supplied either at ambient temperature or refrigerated and/or heated, as desired in particular applications.

A head-worn air pump is provided in a housing, which directs a stream of air to the goggles between the user and the interior surface of the goggles. The housing is mounted to the user's head independently of the goggles. One or more flexible tubes or hoses can be attached to a manifold or plenum at the housing that receives air under pressure from the pump, and extend from the rear of the head to one or both sides of the goggles. The air can be supplied either at ambient temperature or refrigerated and/or heated, as desired in particular applications.

A helmet has a helmet shell and a visor pivotally connected to the helmet shell. First and second helmet electrical contacts are attached at both sides of the helmet and are adapted for electrically connecting to an electrical power source. First and second visor electrical contacts are attached to each side of the visor. The first and second visor electrical contacts are in contact with the first and second helmet electrical contacts respectively, at at least one position of the pivoting visor. First and second electrical wires are electrically connected to the first and second visor electrical contacts respectively.