The term 'tense-eyed' is a compound word formed from 'tense' and 'eye'. 'Tense' originates from Latin 'tensus', the past participle of 'tendere', meaning 'to stretch'.

'Tense' evolved from Middle English 'tens', from Old French 'tens', from Latin 'tensus'.

Initially, 'tense' referred to something stretched or tight, and it evolved to describe emotional or mental states of tension.