Whether or not something is visual depends on us, the viewers, not on the object in question.<quoted text>
I guess we're talking about the same thing in a different way.
DNA was never invisible - never not visible. It was always visible, we just had to find a way to see it.
There are better ways of describing the characteristics of objects that say nothing of the viewer's perspective.
There are probably objects that humans can't see, that really do exist. They may even reflect light. We wouldn't call those things visible. We would call them invisible. We might be able to detect them with a camera, perhaps, but not with our eyes. They would be visible to the camera, but still invisible to us.
People who have visual hallucinations see things that don't really exist. These hallucinations are visible to them, but invisible to anyone else. The visible/invisible label doesn't necessarily say anything about the object.