Object: To assess the optic and protective properties of antique Inuit snow goggles in a major material.
Methods: Measurements, drawings, photos, and calculation of visual field.
Results: Classification into eleven types of apertures, illustrated and described.
Types A-C have a rectangular slit according to size. D has a separate slit on a separate block for each eye. E has a common slit for both eyes. The other types do not have a rectangular slit: Type F has a common figure-of-eight shaped slit for both eyes, G a drop-shaped slit for each eye, H a triangular slit, I several slits, J a binocular-like and K a round opening, in some cases covered with glass.
The visual field is a compromise between protection and visual power, limited upwards as well as downwards. The visual power is improved and dazzling is prevented (model experiments).
The snow goggles reduced harmful light to 2-8%. These snow goggles do not mist over. Details are described (material, dimensions, blackening, fixation to the head, ornamentation, repairs, unilateral slit occlusion, dating).
Geographic differences: The Greenlandic goggles are often somewhat larger than the Canadian ones, the slit frequently figure-of-eight-shaped or drop-shaped, whereas triangular slits or a goggle for each eye are more common in Canada.