Passage: The cuttlefish changes color not by acquiring pigment but by expanding and contracting thousands of chromatophores already present in its skin. Because this reconfiguration is driven by muscle rather than by any chemical synthesis, it is nearly instantaneous, and the animal can produce patterns faster than a predator can register them. Curiously, cuttlefish are colorblind. How an animal that cannot perceive color nonetheless matches the hues of its surroundings remains contested; one proposal holds that the eye's chromatic aberration, ordinarily a defect, encodes wavelength information the brain can exploit without true color vision. If correct, the hypothesis would mean the cuttlefish sees color in a sense — just not the sense the word ordinarily denotes.