@Breezy

Give me your narrative of how the eye evolved and I'll tell you why I think it's problematic.

Eh, I am bored, so I will bite.

TLDR: evolution over time in response to available information from energy, (specifically the type of energy we call light for eyes.)

The eyes, like any other grouping of cells perform a specific function. In most animal and human terms we call these specialized groupings of cells: sensory organs. Sensory organs can be defined by a grouping of cells that are sensitive to a form of energy and can convert that energy into information to be processed by another specific organization of cells with that function (the brain/central nervous system.)

Early in the evolutionary cycle of progress, the skin organ cells that shielded and contained the more vulnerable cells contained within, through its direct contact of various forms of energy bombarding it, that by pure evolutionary chance with untold trillions of tries every second, that if the same already in place muscle organisms that facilitated movement, digestion, and circulation, worked to move away from the entire organism away from the side that was suffering cell damage/death. Thus the ability for the entire organism to survive, consume and reproduce was increased, allowing that type of organism to gain advantage in a limited resource and dangerous environment. The first, crudest form of sense was formed. (A very crude sense of touch based on cellular damage ultimately derived from energy of electron resistance or excitement when in close contact.)

Organisms skin or outer protective layer that is bombarded with all types of energy form the basis of all sensory organs, organs that in turn can send data to the central nervous system so the entire organism can react.

Fast forward to eyes. In organisms that are exposed to varying levels of energy we refer to light, (not deep in the oceans or ground.) The crudest form probably begins with cellular damage of the skin/shell organ when exposed to excessively high amounts of this light energy compared to normal. The skin was built and adapted to one type of light energy range, and when that changes enough the skin gets damaged at rates it was not designed for. Skin that is lighter and more translucent gets more readily damaged by this energy then thicker, darker, less translucent as the energy cannot pass through as readily. Much like the first crudest senses of touch, the central nervous system can react and move away from this damage. For a crude organism that lacks the ability to regulate its temperature, having an organ that can at this crudest form, sense this type of energy and move towards or away from it can again mean a large advantage in success in the evolutionary process.

Given many many years of evolution, specialized areas of skin that are particular sensitive to this form of energy can develop, a light sensitive organ that can do more then just detect large differences in the rate of light energy hits it and react to damage rates. It begins to be able to detect subtle variances, it can begin to detect the differences of light when something passes between it and the light source. Between the sensory organ and light energy reflecting off of something else. Given enough pure chances, the central nervous system that reacted to these sudden changes in light energy had better survival rates then those that did not. Now this crude sensory organ not only can detect variances in overall light, but use these variances to detect movement based on the patterns of light energy hitting this light sensitive organ. It is beginning to work much like what most people would consider eyes.

From here it is a simple matter of the eye organ through evolution to increase in complexity to give the overall organism better survival rates in the brutal world of evolution in a fixed amount of resources and space. The skin of the eye organ grows to be very translucent to allow more light energy to pass through. A cover to protect this sensitive organ. Ever more sensitive specific function cells working in concert to pick up more variance, pass more information to the central nervous system. A dual lens focus system to focus light energy to gather greater detail, I could go through every step but this post is already way to long.

Eventually we arrive at eyes that are highly complex, and specialized for the use of each type of organism and its needs. Human eyes for instance are specialized to pick up on as much information from light reflecting off of nearby objects to discern friend from foe, danger from safety, and to gain large amounts of information with the objects they interact with. A bird of prey's eye is specialized to see minute movement 100's of feet below of activity and size that indicates their prefered prey, but can not see color differences or fine detail of nearby objects.