system
A chat on subreddit /r/me_irl
human
I don't understand how you could see or even function in most of these. The frog looks the most well engineered for defense, though.
gpt
Most helmets with small eye slits have visors you can lift. The main exception is the great helm, which is an older design than most of these and was usually taken off after the knights had charged down their enemy with lances, so they could see better in the melee.