Superiority of clear-visor safety hat to opaque-visor hat: an evaluation of upper visual-field obstruction

Three subjects were used to compare superior visual-field threshold for 5 North American industry-standard opaque safety hard hats with a prototype clear translucent-visor safety hard hat and a no-hat baseline condition. Average maximum degrees of superior visual field was equivalent for the clear-visor safety hat and no-hat conditions (52.0 degrees versus 48.3 degrees) but the opaque-visor safety hats resulted in only 15.1 degrees. The opaque safety hats were worse than the clear-visor safety hat and no-hat conditions by, on the average, an order of 3. Analysis indicated that visual-field obstruction is a potential problem for wearers of opaque safety hats. Field research will be required to assess the extent of injuries caused by an impaired superior field of vision when wearing opaque-safety-hat visors. The potential positive effects of the clear-visor safety hat on reduction of accidents also must be determined.