晚上，瞳孔放大以便让更多的光线射入。

At night, the pupils dilate to allow in more light.

《柯林斯英汉双解大词典》

病人的瞳孔放大了。

The sick man's pupils were dilated.

《柯林斯英汉双解大词典》

用肉眼看来，很难辨识这些符号，不过通过放大镜你可以看到在右边瞳孔(从画作上看是左边)后隐藏的字母lv。

To the naked eye, the symbols are hard to distinguish, but with a magnifying glass you can see the letters LV behind the right pupil (the left when watching the painting).

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