The 'mahitotsu' part of his name means 'one eye,' and it is said this was derived from the fact that blacksmiths closed one eye to judge the temperature of iron from its color, or another story that blacksmiths had an industrial disease which made one eye blind.
神名の「目一箇」（まひとつ）は「隻眼」（片目）の意味であり、鍛冶が鉄の色でその温度をみるのに片目をつぶっていたことから、または片目を失明する鍛冶の職業病があったことからとされている。