The “Corinthian” helmet (named after the city-state of “Corinth”) was by far the most popular helmet among the Ancient Greeks. Forged from solid bronze, it was an extremely sturdy alternative to the Illyrian style helmet; however, when the Corinthian helmet was first made in 8th century BC, it had some issues. Each Corinthian style helmet had to be made individually for each warrior, which meant that it was not very cost-efficient. Also, the small holes for the eyes, and the tight fit around the ears caused bad vision and impaired hearing in battle. Because the cheek guards were so flexible, the helmet could be pushed up and worn on the top of the head, this is how the Hoplite armies would wear it when not in battle. The Corinthian style helmet eventually died out in early 5th century BC, but it lived on in Italy all the way up until 1st Century BC (Connolly, 60-61).
Connolly, Peter. Greece and Rome at War. London: Greenhill ;, 1998. Print.