If you wanted someone to pass you one of two cups, you would need to first compare them and then mention some distinctive property of the cup you wanted; perhaps its colour, or its size. In this talk, I will argue that perceptual contrast not only guides the canonical use of adjectives (i.e. to discriminate amongst objects of the same kind) but also redundant uses (e.g., your referring to a single cup as ‘the red cup’). Redundant referential expressions pose a challenge for pragmatic accounts in the Gricean tradition, but such accounts often fail to take into account perceptual factors (e.g., whether the cup is the only red object on the table). I will report the results of a series of language-production studies supporting the hypothesis that speakers use redundant modification to exploit a perceptual contrast in the environment, as well as parallel eye-tracking experiments showing that such redundant uses facilitate the listener’s visual search for the referent. These studies also compare languages with different adjective positions (e.g., ‘the redcup’ vs. ‘la taza roja’) and show how efficiency is preserved across languages. I will close with some preliminary results of a referential communication study with blind, sighted and newly-sighted children in connection with Project Prakash. Overall, the results of these studies suggest that referential communication runs efficiently, even when we use redundant referential expressions.