But what does it mean to “see” something?
You start with a nerve cell sensitive to electromagnetic radiation of a particular band of wavelengths. If enough photons strike enough photosensitive chemicals and convert them to another form, the nerve cell discharges which tells the “brain” that a certain amount of light was present. Put an array of those sensors and you’ve got a simple eye that can detect light and dark, even more and the eye can detect movement. Put a lens on a large array of these cells and you’ve got a real eye that can detect images. Feed the output of the eye into a complex processing center and you’ve got SIGHT.
Sight is easy to understand. Humans have thousands or millions of sensory nerves feeding information into our visual centers, but lots of other animals have very simple eyes that started as something not much different than skin that can sense heat. It’s a mistake to imagine that we just open our eyes and percieve reality unmediated. The human eye doesn’t see what you think it sees, and this can be demonstrated by all the various optical illusions you see. Blind spots that you can’t “see”. Persistance of vision. Color perception influenced by dozens of different things. And on and on. Try looking at footage from a shaky handheld camera and you’ll get sea-sick…but the guy who took that footage while looking through that camera viewfinder was NOT seasick…in fact he might not have even noticed that the camera was shaking. You see a lot less than you think you do, you can only see a very small part of your visual field clearly…but it seems like you can see everything clearly because every time you look at something it’s clear! Your brain fills in an almost unbelievable amount of information, combines it all into a whole, and you have a sense of just looking out and seeing things. But that’s not really happening!
Same thing with hearing. Hearing is just an elaboration of the sense of touch, just like a cat’s whiskers. Smell is trickier, humans have a very poor sense of smell, but you’ve got an array of chemosensitive nerves in your nose, and when enough of the correct aerosolized molecule binds with the chemical receptors in the olfactory receptor nerves the nerve discharges.
So a radiation sensor, or an electrical sensor, or a chemical sensor, or an x-ray sensor, or an N-ray sensor would be the same thing. The nerve cell is sensitive to stimulus N, enough of stimulus N and it discharges. This is how all senses work. It just happens that our sensors and processors for electromagnetic radiation in the visible wavelengths has been developed to an incredible degree over the last 650 million years of multicellular life.