None so blind as those who will not see

Meaning: Nobody is blinder than the person who decides he does not want to see. Often used in reference to prejudice and intolerance.

Note: none (pronoun): no person; no one | blind (adj.): unable to see; not having the power of sight | will (verb): intend; desire [this is "will" used as a main verb, not as a modal auxiliary verb] | Also: "There's none so blind as those who will not see."