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走遍五湖四海的討海人前輩果然見多識廣，厲害！orz^19748！
以正常人類的標準來說，狗的確是deuteranopia！
轉貼wiki：Like most mammals, dogs are dichromats and have color vision equivalent to red–green color blindness in humans (deuteranopia). So, dogs can see blue and yellow, but difficult to differentiate red and green because dogs only have two spectral types of cones photoreceptors, while normal humans have three cones. And dogs use color instead of brightness to differentiate light or dark blue/yellow……