translation.en: And then when you add the lens to that, you can bundle the light and send it wherever you need it without any need to spill any light to the sky or anywhere else.
translation.zh: 然后在上面加上一块透镜片， 就可以将光聚在一起照射到理想的地方， 避免光浪费找到 天空或者其他什么地方了。