✔ 最佳答案
This is a question about language and the meaning of words rather than about light. The trouble is that, when you try to get a sensible answer, people often change the meaning of your words.
Okay these are the facts. Sight is achieved by light entering the eye and stimulating the retina. But when we say we see something we mean that light emitted by or reflected from the object makes an image on the back of the eye.
1. Light waves do not reflect or emit other light so you cannot see them in the same way that you can see a tree. But if you put your eye in the way of a ray of light then your eye is stimulated. Is that seeing the light? You decide.
2. Again it's your choice. It is the light that stimulates the eye but it is the image that gives us useful information such as the shape of the lamp.
The way I see it is that you see with your brain and it is the useful information that defines sight. Consequently I say that you see with light but you cannot see light itself. But that is just my opinion. You choose what you mean by seeing.
As regards your coda, visible light is simply a shorthand phrase. Light stimulates the eyes whereas other electromagnetic radiation such as infrared, radio, ultraviolet and xrays do not. So see say visible and invisible light because it is a lot quicker and simpler than saying radiation that can stimulate the eye. As long as we know what we mean, it doesn't matter that the phrase is actually meaningless.
