Your eyes pick up color using a type of cell called cones in your retina. The same is true for dogs, though our cones aren't exactly the same.
人類的眼睛通過視網(wǎng)膜的視錐細(xì)胞感知顏色,狗也是如此,但兩者的視錐細(xì)胞并不完全相同。
Humans have three types of cones, "which enables us to see different shades of red, blue-violet, and green," says Alison Meindl, DVM, a veterinarian, and professor at Colorado State University.
科羅拉多州立大學(xué)教授、獸醫(yī)學(xué)博士、獸醫(yī)艾莉森·梅恩德稱,人類有三種視錐細(xì)胞,“因此我們能夠看到不同深淺的紅色、藍(lán)紫色和綠色。”
Dogs have two types of cones that pick up blue-violet and yellow shades, says Lara Sypniewski, DVM, a professor of small animal medicine at Oklahoma State University.
俄克拉何馬州立大學(xué)小型動(dòng)物醫(yī)學(xué)教授、獸醫(yī)臨床醫(yī)生拉臘·西普尼夫斯基稱,狗有兩種視錐細(xì)胞,可以分辨藍(lán)紫色和黃色。
This means that dogs see in a similar way to humans who are red-green colorblind. "They don't see red or green and they see everything in shades of blue and yellow," says Jay Neitz, Phd, a researcher and professor of ophthalmology at the University of Washington.
這意味著狗的視覺與紅綠色盲的人相似。華盛頓大學(xué)眼科教授、研究員杰伊·內(nèi)茨博士稱,“狗看不見紅色或綠色,但能看到所有藍(lán)黃色調(diào)的顏色。”
Humans may have the advantage in color vision, but dogs definitely have us beat in the realm of night vision. This is because dogs' eyes have more light-gathering power than ours, Neitz says.
人類在色覺方面可能有優(yōu)勢(shì),但狗的夜視能力肯定比人類強(qiáng)。內(nèi)茨說,這是因?yàn)楣返难劬Ρ热说难劬Ω酃狻?br />
A dog's retina is largely composed of cells called rods, which can sense light, even in very low-light conditions, says Sypniewski.
西普尼夫斯基說,狗的視網(wǎng)膜主要由視桿細(xì)胞組成,即使在光線很弱的情況下,視桿細(xì)胞也能感知光線。
Dogs are especially good at sensing movement. "The increased number of rods in the dog's retina also increases their ability to detect motion," Sypniewski says. This ability can help them detect small prey like squirrels.
狗特別擅長(zhǎng)感知運(yùn)動(dòng)。西普尼夫斯基說:“狗的視網(wǎng)膜中視桿細(xì)胞數(shù)量多,這使得它們觀察運(yùn)動(dòng)的能力更強(qiáng)。”這種能力可以幫助它們發(fā)現(xiàn)像松鼠等小獵物。
Dogs have a wider field of vision than humans. Dogs' eyes are set slightly farther apart than humans' eyes, so they can see further to the side in each direction.
狗的視野比人類更廣。狗比人的眼間距稍遠(yuǎn),因此它們可以在每個(gè)方向上看得更遠(yuǎn)。
Dogs have blurrier long-distance vision than humans. A human with perfect vision has 20/20 vision, while dogs have 20/65 to 20/85. This means that "a dog must be at 20 ft. to read a letter that a human with 20/20 vision would be able to read at 65 or 85 ft.," says Sypniewski.
狗的遠(yuǎn)距離視力比人類更模糊。擁有完美視力的人類有20/20的視力,而狗有20/65至20/85的視力。這意味著“狗必須在20英尺(約合6米)處才能看見一個(gè)擁有20/20視力的人類在65或85英尺處能看到的字”。
Dogs have trouble seeing things very close up. Dogs can see objects clearly if they're at least 13 to 20 inches away from their eyes, "but if the object is closer, the image may be blurry," Sypniewski says. Humans can see objects slightly closer — about 10 inches away from the eye.
狗很難近距離觀察事物。“當(dāng)物體距離眼睛至少13到20英寸(約0.3到0.5米)遠(yuǎn)時(shí),狗狗能看清楚,”但如果物體更近,眼中的圖像可能就會(huì)模糊不清。人類可以看到更近的物體,大約到10英寸(0.25米)遠(yuǎn)。
Dogs may recognize you by your shape and motion. "If your dog recognizes you from a distance, it is not because it can see the details of your face like a human would, but rather because of your shape or the way you move," Neitz says.
狗可以通過身形和動(dòng)作識(shí)人。內(nèi)茨說:“如果你的狗能從遠(yuǎn)處認(rèn)出你,那不是因?yàn)樗芟袢祟愐粯涌辞宄愕哪?,而是因?yàn)檎J(rèn)出你的身形或移動(dòng)方式。”