Eye EM Spectrum Sensitivity

Hello. I see you!

Okay, so we live on Earth, like, du'UH! And our eyes, those two shiny looking piece of pearl-like contraption we like to spoil are adapted to a specific band of electromagnetic radiation wavelengths...right? Because our Sun, Sol, gives off light in a variety of wavelengths, but the most prominent of these wavelengths happen to fall within a thin band we egoistically call "visible light", our eyes, and the eyes of most life on Earth are adapted to receive this stimuli. A few others does away with eyes, and some see in infrared red.

Anyway, examining the construction of our eye, we can see that two types of cell groupings are responsible for sight; cone cells responsible for daylight vision, and rod cells for nighttime vision. Cones need a lot of stimulus to be activated, while rods need only a few photons. Now, assuming that we can manipulate our DNA; which by the way is way past the time to dilly dally; can we make our eyes a little more sensitive to other wavelengths? Say for example...infrared red? So instead of seeing "visible light", we'll be seeing...heat light. Now further assuming that we can see; for lack of a better word; heat, and not see the current "visible light" anymore, would "visible light" then be defined as heat light (aka infrared red, IR)?

What if we were made to be sensitive to both IR and VL (visible light)? Can we switch between them just like we blink? How about if we were able to see in ultraviolet? Or even perceive X-ray band wavelengths? Would it be possible? Would it be better than the cumbersome and unsophisticated machine equivalents? Would voyeurism rule?

I for one would like IR and VL vision rolled into two tiny packages that is our eye. That way, nighttime driving would be so much saner, and nighttime jungle trekking would be so much funner. What you like?