Great question! An important reason that humans, and most animals, do not see wavelengths that neighbor the visible ones, even though the Sun produces significant ultraviolet and infrared radiation, is that the ultraviolet and infrared rays do not penetrate below the upper few centimeters of the surface waters of the ocean. Why should this matter to humans? Because we inherit our "vision equipment" from lower life forms that evolved in ocean waters. After those early single and multicell life forms evolved, later the evolution of the human brain modified human vision and other capabilities. Yet still human (and animal) eyes continue to "detect" best in the visible wavelengths, because that is all that was detectable by our evolutionary ancestors that did not live on land. [e.g. Segelstein, D. 1981. The complex refractive index of water. M.S. thesis. University of Missouri, Kansas City, MO.]