What it means:
This phrase has more than one meaning: we overlook flaws in those we love (that's good), but love can blind us to serious issues (that's bad).
How Shakespeare used it:
In The Merchant of Venice, Jessica is shy about her beloved Lorenzo seeing her disguised as a boy, but recognizes that it won't affect his love for her, saying, "But love is blind and lovers cannot see / The pretty follies that themselves commit ..." (Act 2, Scene 6)
(The phrase also appears in Henry V and The Two Gentlemen of Verona.)
"Jonathan Rhys Meyers thinks love is blind. The actor ... thinks it is easy to fall for someone without knowing much about them, just like his alter-ego does...." ShowbizSpy.com, Feb. 7, 2010