"Coming up with a good eye" is not an evolutionary goal because evolution does not have goals. Any concept of the eye being some sort of finished product, or achievement, betrays the conceiver as someone who does not understand how evolution works. Neither is it right to think of it as a step towards some notion of perfection. It is what it is and it "got there" with many a slip and blind ending :-) along the way, and it's been billions of years in the making (the terrifying time-span of life on earth is the main notion that completely eludes people who doubt evolution's ability to get things done). In its own way, your big toe nail is just as "wonderful". Or your anus even. Doubly wonderful when you see how creationists can talk out of it.