blindyoudaoicibaDictYouDict[blind 词源字典]
blind: [OE] The connotations of the ultimate ancestor of blind, Indo-European *bhlendhos, seem to have been not so much ‘sightlessness’ as ‘confusion’ and ‘obscurity’. The notion of someone wandering around in actual or mental darkness, not knowing where to go, naturally progressed to the ‘inability to see’. Related words that fit this pattern are blunder, possibly from Old Norse blunda ‘shut one’s eyes’, blunt, and maybe also blend.

By the time the word entered Old English, as blind, it already meant ‘sightless’, but ancestral associations of darkness and obscurity were retained (Pepys in his diary, for instance, writes of a ‘little blind [that is, dark] bed-chamber’ 1666), and traces of them remain in such usages as ‘blind entrance’.
=> blend, blunder, blunt[blind etymology, blind origin, 英语词源]
blind (adj.)youdaoicibaDictYouDict
Old English blind "blind," also "dark, enveloped in darkness, obscure; unintelligent, lacking mental perception," probably from Proto-Germanic *blinda- "blind" (cognates: 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" (see bleach (v.)). Compare Lithuanian blendzas "blind," blesti "to become dark." The original sense would be not "sightless" but rather "confused," which perhaps underlies such phrases as blind alley (Chaucer's lanes blynde), which is older than the sense of "closed at one end" (1610s).
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]
In reference to doing something without seeing it first, by 1840. Of aviators flying without instruments or without clear observation, from 1919. Related: Blinded; blinding. Blindman's bluff is from 1580s.
blind (v.)youdaoicibaDictYouDict
"deprive of sight," early 13c., from Old English blendan "to blind, deprive of sight; deceive," from Proto-Germanic *blandjan (see blind (adj.)); form influenced in Middle English by the adjective. Related: Blinded; blinding.
blind (n.)youdaoicibaDictYouDict
"a blind person; blind persons collectively," late Old Engish, from blind (adj.). Meaning "place of concealment" is from 1640s. Meaning "anything that obstructs sight" is from 1702.