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Name: Robert
Status: student
Age: 10
Location: N/A
Country: N/A
Date: 2000-2001

How do cat's make their pupils smaller?

Hi Robert.

That is a question i answer with great pleasure since a am a cat lover, see?. .Look, the cats are naturally nocturnal animals... Their retina is extra sensible to light, this is due to a layer of guanine, (a colourless, crystalline substance) that causes the eyes to shine at night when are focused by a strong light. The eyes are large and, as you noticed, the pupils expand or contract to mere slits according to the density of light. That is, the pupils react to the quantity of light, if it is great they get smaller so the quantity of light that enters and hit the retina is small. At night when it gets dark, the pupils become larger allowing all the local light to enter it. That is also why people says that cats see in the dark...All that happens due to adaptation to the environment.

Thanks for asking NEWTON!

(Dr. Mabel Rodrigues)

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