Why do we have these eyes?

Worry , I will not make you a course of advanced eye care!
But let us reflect for a moment on the nature of things. Our eyes (how many of you have thought?) seem so perfect that anyone has even dared to take such evidence and that some god created us so specially. But in fact, going to better analyze this organ so special and wonderful, yet it is the result of billions of years of evolution, from early ommatidia ocelli and jellyfish, to the compound eyes of trilobites and finally those of vertebrates, there realize that still have imperfections due to the randomness of evolution without any plan sentient and intelligent, as the blind spots of the retina and the entire eye field, the lens stiffens that after a certain age making us presbyopia, the inability to perceive all the wavelengths of the electromagnetic spectrum, as can instead maybe to other animal species, in turn inette to see color in the visible as we do. It would seem a miracle that we see in the visible range only very small so many beautiful colors, but the explanation is simply that the shield of the Earth's magnetosphere firm charged particles such as alpha and beta rays with the solar wind flow . Photons have no electric charge rather than go quietly, except for those at higher frequency as UV and X-rays that are blocked by the ozone layer (a particular cationic form of molecular oxygen that we need to thank for cyanobacteria and stromatolites have saturated the ' atmosphere in the distant past of our planet). Then the eyes of all living things have evolved to take advantage of the one and only wave frequencies that could pass this double shield. Including the third eye of some reptiles that senses the infrared. If we had originated on another planet with different characteristics, in fact, probably those same radiation and / or charged particles that define harmful and for which we thank God or fate for having had the kept at bay, the recommend taking advantage to see or perceive the surrounding environment, maybe because visible light would be absent or reduced, filtered by other planetary conditions. We would have had other sense organs evolved for those particular circumstances, as well as adequate defenses against ionizing radiation that we do not have here on Earth instead, there being any need (and in fact the astronauts when they go into orbit to fiddle with the technology, they absorb not a few , when you just do not risk your skin, if it were a surprise CME) and, if we were sentient, probably would say: "Thank God that visible light (in fact, I wonder how we were called, because for us it would have been visible a very different spectrum!) does not reach us, or we would have blinded! praise be to the person who created all this "(but I like to think that elsewhere in the cosmos to reason better and that things like this do not transgresses the boundaries of our planet.