Why can't low frequency or high frequency light enter my eye just like ordinary light? I imagine an ordinary camera should be able to detect light if it enters the lens, no matter the frequency. Am I under a misapprehension about cameras? Why can't the eye do the same? I know this is a physics forum, but could the explanation be that we evolved to see visible light because it is more useful than lower/higher frequencies? Perhaps the answer is in biology. But whatever, I'm sure you guys will set me straight.