Definition of gravel-blind in English:

gravel-blind

adjective

archaic
  • Almost completely blind.

    • ‘This Is my true-begotten lather, who, being more than sand-blind, high gravel-blind, knows me not.’
    • ‘It was natural that the descendant of the Incas should desire to relieve his race from so odious an imputation; and we must have charity for him, if he does show himself, on some occasions, where the honor of his country is at stake, "high gravel-blind."’
    • ‘Depending on his reduced power, a person can be calassified as 'stone-blind' or 'gravel-blind'.’

Origin

Early 17th century: originally as high-gravel-blind, a humorous usage meaning ‘more than sand-blind (= half-blind’), with reference to Shakespeare's Merchant of Venice.