你可以说 "It's too dark" 或者 "It's too dim" 来表示光太暗了。这个表达方式源自于英语中的 "dark" 和 "dim" 这两个词，分别表示 "黑暗的" 和 "昏暗的"。

一些英文例句及其中文翻译如下：

It's too dark to see. (光太暗了看不见。)
The room was so dim that I couldn't make out the faces of the people in the back. (房间太暗了，我看不清后面的人的脸。)
I can't read this book in the dark. Can you turn on the pght? (我不能在黑暗中看这本书。你能打开灯吗？)
It's hard to find my way in this dimly pt hallway. (在这条灯光昏暗的走廊里找路很困难。)