WordNet sense 1 (a hazy or indistinct representation):

fuzz

WordNet sense 2 (become glassy; lose clear vision):

film over, glaze over

WordNet sense 3 (make a smudge on; soil by smudging):

smear, smudge, smutch

WordNet sense 4 (make unclear, indistinct, or blurred):

confuse, obscure, obnubilate

WordNet sense 5 (make dim or indistinct):

blear

WordNet sense 6 (become vague or indistinct):

dim, slur