cockeyed adj.

mid-12c., cocken, "to fight;" 1570s, "to swagger;" 1640s as "to raise or draw back the hammer or cock of a gun or pistol as a preliminary to firing." Seeming contradictory modern senses of "to turn or stand up, turn to one side" (as in cock one's ear), c. 1600, and "to bend" (1898) are from the two cock nouns. The first is probably in reference to the posture of the bird's head or tail, the second to the firearm position.

To cock one's hat carries the notion of "defiant boastfulness." But a cocked hat(1670s) is merely one with a turned-up brim, such as military and naval officers wore on full dress occasions.

To go off half-cocked in the figurative sense "speak or act too hastily" (1833) is in allusion to firearms going off unexpectedly when supposedly secure; half-cocked in a literal sense "with the cock lifted to the first catch, at which position the trigger does not act" is recorded by 1750. In 1770 it was noted as a synonym for "drunk." 

c. 1200, from Old English ege (Mercian), eage (West Saxon) "eye; region around the eye; apperture, hole," from Proto-Germanic *augon (source also of Old Saxon aga, Old Frisian age, Old Norse auga, Swedish öga, Danish øie, Middle Dutch oghe, Dutch oog, Old High German ouga, German Auge, Gothic augo "eye"). Apparently the Germanic form evolved irregularly from PIE root *okw- "to see."

HAMLET: My father — methinks I see my father.

HORATIO: Where, my lord?

HAMLET: In my mind's eye, Horatio.

Until late 14c. the English plural was in -an, hence modern dialectal plural een, ene. Of potatoes from 1670s. Of peacock feathers from late 14c. As a loop used with a hook in fastening (clothes, etc.) from 1590s. The eye of a needle was in Old English. As "the center of revolution" of anything from 1760. Nautical in the wind's eye "in the direction of the wind" is from 1560s.

To see eye to eye is from Isaiah lii.8. Eye contact attested from 1953. To have (or keep) an eye on "keep under supervision" is attested from early 15c. To have eyes for "be interested in or attracted to" is from 1736; make eyes at in the romance sense is from 1837; gleam in (someone's) eye (n.) "barely formed idea" is from 1959. Eye-biter was an old name for "a sort of witch who bewitches with the eyes."