(fig.) (of one's actions) blind; unthinking

I never know what to say to people who have absolutely no grasp of the basic facts and are too ignorant to realise it.

Jane is fat and rude, and smokes too much. However, Ken thinks she's lovely and charming. That's why they say love is blind.

Love blinded him to her faults.

Love is blind, but jealousy can see even nonexistent things.