Green eyeshade

Green eyeshades are a type of visor that were worn most often from the late-19th century to the mid-20th century by accountants, telegraphers, copy editors and others engaged in vision-intensive, detail-oriented occupations to lessen eyestrain due to early incandescent lights, which tended to be harsh (the classic banker's lamp had a green shade for similar reasons). Because they were often worn by people involved in accounting, auditing, economics, and budgeting, they became associated with these activities.