Old English blind "destitute of sight," also "dark, enveloped in darkness, obscure; unintelligent, lacking mental perception," probably from Proto-Germanic *blindaz "blind" (source also of Old Frisian, Old Saxon, Dutch and German blind, Old Norse blindr, Gothic blinds "blind"), perhaps, via notion of "to make cloudy, deceive," from an extended Germanic form of the PIE root *bhel- (1) "to shine, flash, burn."
The original sense would be not "sightless" but rather "confused," which perhaps underlies such phrases as blind alley (1580s; Chaucer's lanes blynde), which is older than the sense of "closed at one end" (1610s).
Meaning "not directed or controlled by reason" was in Old English. Meaning "without opening for admitting light or seeing through" is from c. 1600. In reference to acting without seeing or investigating first, by 1840; of aviators flying without instruments or without clear observation, from 1919.
The twilight, or rather the hour between the time when one can no longer see to read and the lighting of the candles, is commonly called blindman's holiday. [Grose, 1796]
c. 1200, literally "wind eye," from Old Norse vindauga, from vindr "wind" (see wind (n.1)) + auga "eye" (from PIE root *okw- "to see"). Replaced Old English eagþyrl, literally "eye-hole," and eagduru, literally "eye-door." Compare Old Frisian andern "window," literally "breath-door."
Originally an unglazed hole in a roof. Most Germanic languages later adopted a version of Latin fenestra to describe the glass version (such as German Fenster, Swedish fönster), and English used fenester as a parallel word till mid-16c.
Window dressing in reference to shop windows is recorded from 1853; figurative sense is by 1898. Window seat is attested from 1778. Window of opportunity (1979) is from earlier figurative use in U.S. space program, such as launch window (1963). Window-shopping is recorded from 1904.
Window shopping, according to the women, is the king of outdoor sports. Whenever a woman gets down town and has 2 or 3 hours and no money to spend, she goes window shopping. She gives the Poiret gowns and the thousand dollar furs the double O and then kids herself into believing she'd look like Lillian Russell or Beverly Bayne if she had 'em on. It's great for developing the imagination and one of the great secrets of conserving the bankroll. ... [Motor Age, Jan. 27, 1916]
"make blind, deprive of sight," early 13c., from Old English blendan "to blind, deprive of sight; deceive," from Proto-Germanic *blandjan (source also of Old Frisian blinda, Dutch blinden, Old High German blinden "become blind;" Danish blinde, Gothic gablindjan "make blind"), perhaps, via notion of "to make cloudy, deceive," from an extended Germanic form of the PIE root *bhel- (1) "to shine, flash, burn (see blind (adj.)). Form influenced in Middle English by the adjective. Related: Blinded; blinding.