Historical clue formulations

• Way things look to the public, informally — 2020-06-23
• Concern for a P.R. team — 2020-06-07
• Public perception, in political lingo — 2020-01-07
• Public perception — 2018-02-17
• Science of light — 2014-01-02
• Field of vision? — 2005-12-01
• Field of vision? — 2001-06-07
• High-tech subject — 1999-05-08
• Branch of physics — 1997-08-21
• Study of light — 1994-06-19