By virtue, humans eye can only see EM wave in the visible light region. From my understanding of 'why we see things', it is because light reflect off an object and the lights' diffraction patterns that enter our eyes determine our ability to resolve it.
My textbook then says "the wavelength of visible light is too long for light to interact effectively with individual atoms and molecules."
However, what exactly does "interact effectively" mean? Does it mean light don't reflect from individual atoms or molecules? If so why would the wavelength of a wave affect its ability to reflect off a small thing e.g. an atom?