What does "blear" mean?

Blear: Causing or caused by dimness of sight; dim. Power to cheat the eye with blear illusion. Milton.

Additional senses

  1. 2.To make somewhat sore or watery, as the eyes; to dim, or blur, as the sight. Figuratively: To obscure (mental or moral perception); to blind; to hoodwink. That tickling rheums Should ever tease the lungs and blear the sight. Cowper. To blear the eye of, to deceive; to impose upon. [Obs.] Chaucer.

Sources