British 55th (West Lancashire) Division troops blinded by tear gas wait in line to be treated at a dressing station near Béthune, France, during the Battle of Estaires in 1918. (2nd LT. T.K. Aitken/Imperial War Museums Via Getty Images)
British 55th (West Lancashire) Division troops blinded by tear gas wait in line to be treated at a dressing station near Béthune, France, during the Battle of Estaires in 1918. (2nd LT. T.K. Aitken/Imperial War Museums Via Getty Images)