Keeping a pet cat puts owners at greater risk of going blind, but a dog appears to protect eyesight, a new study suggests.
一項最新研究表明，養貓會增加主人失明的風險，但是養狗卻能保護主人的視力。

Scientists have discovered that dogs and cats carry antigens which can prompt different immune responses in humans.
科學家們發現狗和貓身上都攜帶能激起人體的不同免疫反應的抗原。

While the allergen which dogs carry reduces the chance of developing glaucoma – the second leading cause of blindness in theUK– owning a cat nearly doubles the risk of contracting the eye disease.
狗身上攜帶的過敏原會降低主人患青光眼的幾率，在英國，青光眼是導致人們失明的第二大誘因，而養貓讓主人感染這一眼疾的風險增加了一倍。

Many pet owners suffer mild allergic reactions to their pets but still choose to keep them. However the new study suggests that even a small immune response could lead to blindness.
許多寵物主人對他們的寵物都有輕微的過敏反應，但是卻堅持養寵物。然而最新研究表明，即使是個很小的免疫反應都有導致失明的危險。

The study by the University of California, Los Angeles, found that cat owners who reacted to their pet allergen had a 90 per cent increased risk of glaucoma compared with non-pet owners. But dog owners were 20 per cent less likely to develop the debilitation condition.
加州大學洛杉磯分校的這項研究發現，如果寵物貓的主人對他們的寵物過敏的話，其患青光眼的風險比沒養寵物的人高90%。但是，寵物狗的主人出現視力減弱的幾率卻很可能比一般人低20%。

Keeping a dog also has the added benefit that owners are outside more which has been proven to protect against short-sightedness.
養狗的主人需要經常在戶外活動，這同時也有助于保護主人的視力，不會近視。

“Not only is Fido man's best friend, he may also save your sight,” said British laser eye surgeon Dr David Allamby.
英國激光眼科醫生大衛·阿蘭比博士說：“寵物狗不僅是人類最好的朋友，還可以保護你的視力。”

“Cats could cause our immune system to react in a way that predispose eyes to the development of glaucoma.
“而寵物貓卻會誘發我們的免疫系統做出不同的反應，導致青光眼的出現。”

“Exposure to dogs appears to be linked to the opposite effect and could be protective against the disease.”
“與狗接觸卻會產生相反的作用，并且還能防青光眼。”

Glaucoma occurs when fluid in the eyeball stops draining efficiently, causing a build-up of pressure which damages the optic nerve and nerve fibres from the retina. Previous studies have suggested that inflammation can drive the disease and the researchers wanted to find out if that could be triggered by pet allergens.
青光眼是由于眼球中的液體不能有效排出，導致眼內壓力累積，從而導致視網膜的視神經和神經纖維受損導致的。早前的研究表明炎癥能引起青光眼，研究人員同時還想弄清楚，寵物過敏原是否也會導致青光眼。

Animals frequently groom themselves so allergens from saliva and secretions spread throughout the home, becoming airborne easily where they can be inhaled by humans.
由于動物們頻繁地梳理它們自己，所以來自唾液和分泌物的過敏原很快就擴散到整個家里，接著又通過空氣傳播很容易就被人類吸入體內。

The researchers believe that dogs are healthier for humans because they spend more time outdoors.
研究人員認為，對人類來說，狗更健康一些，因為它們大多數時間都在戶外。

“The protective effect of dogs could be due to their natural antigens in their dead skin, but might also be because they spend more time outdoors and are happy to get dirty, whereas cats are cleaner animals,” said Dr Anne Coleman, of UCLA.
加州大學洛杉磯分校的安妮·科爾曼博士表示：“狗的防護作用可能是來自于它們死皮內的自然抗原，但是也可能是由于它們更多時間都在戶外，而且把自己弄臟了也很開心，然而，貓卻是種愛干凈的動物。”

“We already know that exposure to dogs and the germs and bacteria they carry can be good for the immune system. Now it seems to be the case for the eyes too.
“我們已經知道接觸狗和它們攜帶的細菌對人類免疫系統有益。現在發現這似乎對人類的眼睛也有益處。

“Allergens from cats may have biochemical or physical properties that trigger antibodies targeting the optic nerve, while dog allergens may behave differently, possibly because dogs spend more time outdoors."
“貓身上攜帶的過敏原可能有生物化學性或物理性特征，能誘發針對視神經的抗體，而狗身上攜帶的過敏原起到的作用卻不同，可能是因為狗大多數時間都在戶外。”

Vocabulary:

antigen: 抗原

glaucoma: 青光眼

debilitation: 衰弱變化

predispose: 使傾向于

retina: 視網膜

inflammation: 炎癥

saliva: 唾液

secretion：分泌物

（翻譯：燕子雙飛 編輯：Helen）