听力文本

And floaters are particularly noticeable when you are looking at a uniform bright surface,
“飞蚊”也会很明显比如当你盯着发光的表面时，
like a blank computer screen, snow, or a clear sky, where the consistency of the background makes them easier to distinguish.
像是空白的屏幕雪或是晴空，因为颜色一致的背景会使“飞蚊”更明显。
The brighter the light is, the more your pupil contracts.
当看到的光越亮瞳孔会收缩的更厉害。
This has an effect similar to replacing a large diffuse light fixture with a single overhead light bulb,
这就好比把许多散射的光换成一个大的聚光灯
which also makes the shadow appear clearer.
也会使得阴影更加明显。
There is another visual phenomenon that looks similar to floaters but is in fact unrelated.
另外也有一种视觉现象与飞蚊症类似但与之无关。

If you've seen tiny dots of light darting about when looking at a bright blue sky,
当你仰望蓝天时会看到小光点在快速闪动，
you've experienced what is known as the blue field entoptic phenomenon.
这被称之为谢瑞尔氏现象。
In some ways, this is the opposite of seeing floaters.
这与看到飞蚊相反。
Here, you are not seeing shadows but little moving windows letting light through to your retina.
此时，你看到的不是阴影，而是一些移动的小开口让光进入视网膜。
The windows are actually caused by white blood cells moving through the capillaries along your retina's surface.
这些开口是由白细胞造成的白细胞穿梭在视网膜表面的毛细血管。
These leukocytes can be so large that they nearly fill a capillary causing a plasma space to open up in front of them.
白细胞可以大到填满整个毛细血管，这导致了白细胞身前的空隙。

演讲介绍

我们有时会突然发现，视野里有像灰尘或者虫子样的透明物体在飘荡，目光尾随过去又会立刻消失，非常奇妙。对此，向学生提供教育内容的TED-Ed通过图片解说了这种“透明漂浮物”的真面目。