Why do cat eyes change 3 times a day?

Chinese folk have a saying about the 3-day dilatation of cat's pupils: 'Gradual, crown, body, rooster like apple seeds; Thin, scrawny, silky, smell like thread; Ty, huu, teo, like a full moon '. What makes cat eyes have that power?

Explaining the cause of cat eyes strange changes in the day

So, the cat's pupil (pupil) is very big, and the spasticity of the sphincter in the pupil is very strong. In humans, if you look closely at the sun, the pupils of the eyes will shrink. But we can only see to a certain extent, can not shrink any more, because it will feel sore eyes for a long time. And if you squint a little while in the dark, you will feel dizzy.

The pupil of the cat's eyes can shrink very small to adapt to strong light. (Photo: users)

But cats, under the illumination of light are not the same, can adapt very well. Under very strong light during the day, the cat's pupils can shrink very small, like a thread. At night it was dark, the pupils could open as big as the full moon. Under the intensity of the light in the early morning or the dark night, the iris will have an apple- shaped shape .

Thus the pupil of the cat's eye is capable of shrinking greatly compared to the pupil in the human eye, so the ability to react to light is also more sensitive than us. So, whether the light is too strong or too weak, the cat still clearly sees the objects as usual.