That's not explaining anything, evolutionary scientists assume the eye evolved bit by bit by time and chance, there is no real scientific method of explanation, there is no working model for eye evolution, which bit of the human eye evolved first?
No, it is a complete and sound explanation that fits the evidence without contradiction. Photosensitive cells exist in the simplist organisms. Even a sunflower through pure photomechanical means rotates its flower head to point at the sun, rotating through the day. Many other flowers have similar mechanisms to open u and close their flower head in the morning.
Many single cell organisms are also photosensitive.
The first eyes were nothing more than photosensitive cells (which have proven ly been evolved countless times throughout history in many different shapes and forms). In multicelled organisms a few photosensitive cells roughly arranged is all that is required for the organisms to perform tasks such as phototaxis, e.g. Hide in the shadows during the day and only come out at night.
Te modern complex eye is nothing more than a collective of photosensitive cells that are more tightly packed than primitive ancestors. It is the processing of the visual field which is actually much more interesting. And here there are fascinating modern results that are found through cross model similarities within the computer vision And artificial evolution community. Many of the modern techniques for image processing have very similar biological counterparts, and furthermore, artificial evolution and genetic algorithms applied to neural-visual processing has indepently evolved with simulation the basic building blox of visual comprehension such as edge detection, image pyramids, optical flow computation, etc., etc.
The thing is with the eye, it is deemed by religious fanatics to be some kind of evolutionary mystery. But it is not in the slightest. It is actually incredly well understood and has been shown to have indepently evolved numerous times with the basic building blocks being in existence since the dawn of life. Why is it that such nutcases have such a difficulty in comprehending how photosensitive cells that merely comvert electromagnetic energy in the form of photons into electrons is very primitive, yet the more complex process done by plants to convert photons into chemical energy through photochemical reactions, I.e photosynthesis. Photosynthesis is exactly far more complex and to be fully understood requires invoking quantum mechanics models! Photosensitive cells really only require high school physics to understand.
To back this up we have countless ways in which we have mimicked the eye and convert photons to electrons across an array, it is called a digital camera, but even a solar panel is doing much the same thing. What we haven't managed to replicate successfully at industrial levels is photosynthesis.