The word “blind” as in curtain obviously comes from same term meaning “unable to see.” When a window is covered up with a curtain who becomes blind? The outsiders are blind to what is happening inside, the insiders are blind to what is happening outside, or maybe the people inside can no longer see because of lack of sunlight.
Let us look at history to see what was most likely meant when the word was first used to refer to curtains.
Firstly note that use of “blind” as in “unable to see” was first used in Old English in year 1535 (wiki dictionary). It was probably only until much later that the word was used to mean a curtain.
Black-out blinds during Wartime
The first use of enforced blackouts was in the beginning of World War One. Right at the beginning of the war Germany planned the first ever strategic air bombing campaign on England. Before the war Winston Churchill, lord of the Admiralty, planned to blackout the coastal towns to confuse German submarines as well aircraft. Eight days after England declared war on August 12 1914 the blackout was issued on several towns. Germany started air-raids on England on England first with Zeppelins then with Gothas bomber planes. In response the whole England was put under nightly blackouts by February 1916.
By World War Two it was common term to use blackout-blinds with black-outs laws issued in many countries around the globe. For as many as five years people grew accustomed to living under blackout conditions. Of course everyone was greatly relieved at the end of war when the blackout was finally lifted. During the black many people were injured from automobile accidents as well as suffering high street crime rates.
Black-out blinds available at Royal Window Treatments
My sister married a New York Lawyer bought blackout shades from Royal Window Treatment a year ago for their bedroom. They are extremely safe (unvisible) and happy.