Historical clue formulations

• Widens, as a pupil — 2025-07-01
• Widens, as a pupil — 2023-01-17
• Expands — 2022-04-22
• Lets extra light in, in a way — 2021-11-21
• Works with pupils? — 2018-01-10
• Widens — 2012-07-15
• Expands — 2005-01-27