Where does at a glance come from?
Among other meanings, a glance is a "quick look" at something, dating back to the 1500s. When it first emerges isn't exactly clear, but at a glance became an idiom in Modern English for "upon a quick look." Sir Arthur Conan Doyle used it, for instance, in an 1892 Sherlock Homes story: "It was obvious at a glance that the story of the fuller’s-earth was the merest fabrication..." Elementary.
In the 20th century, at a glance spread as "overiew," ranging from bullet points of complex events or processes (the Civil War at a glance, college enrollment at a glance) to a brand of calendars, At-A-Glance, designed to give people a snapshot of their day, week, or month at a glance. Basically, anything that's complex or at all confusing can be given an "at a glance" form.
— Channel NewsAsia (@ChannelNewsAsia) June 14, 2018
Who uses at a glance?
In everyday speech and writing, at a glance is a shorthand for "shortand." It signals that dense or long information will be presented in an easier and clearer way for us dumb-dumbs so that we quickly get the highlights, the big takeaway, the gist—all with just a skim.
Cardinals draft picks at a glance https://t.co/EYMFTkV4p5
— St. Louis BBWAA (@StLouisBBWAA) June 5, 2018
— BlockPulse (@BlockPulse360) June 10, 2018
Check out the week at a glance for next week / Note no school on Friday for students...
@argyleschoolSK, June, 2018
If a shirt is subtly designed enough that it's instantly recognizable to a fan, while still reading as attractive to an outside observer at a glance, you did good.
@MinovskyArticle, June, 2018
Three men and a baby - today's news at a glance...We might find out today what will happen to three prominent jobs, and there will be a nice story about babies.
BBC (video title), 2016