You tell some good stories. Unfortunately, your "guess" and what you think "perhaps" happened "1 million" years ago is not really the same as the actual truth. It is just a story. Berned asked for a story. His implication was that no such story was possible. As it turns out, such stories are not only possible, but plausible.
But I can do better still: at virtually every step where I described an eye with varying degrees of functionality, we can find eyes in the animal kingdom that remain as I have described.
Eyes also "devolve" when they are not used. Your story is speculation. I can just as easily tell a story about how the eye existed fully formed by God and then it devolved and deterioriated over time when it wasn't used or was not useful for survival. Both of our stories are still stories. Speculation is not the same as reality.