Nobody had to design it. It naturally arises in the conditions in which life existed/exists.
Eyes as a light sensing organ arise quickly (maybe tens of thousands of generations) with even small amounts of selection for light sensitivity.
Quite readily replicated in generative network simulations.
All that said, the real question is how did the conditions get there? Why is the universe and earth in particular so finely tuned?
Pit vipers are on the path to having infrared eyes. The have heat sensors cells, they have them in a cup that shades them from off-axis IR. In the future, if it is adaptive, that pit will turn into something closer to a pinhole camera, then, if it is adaptive, a thin transparent membrane will grow over that pinhole to prevent crud from getting into the eye, if it is adaptive, serpents with membranes thicker in the middle will have better hunting success with even that crude lens. Oh wait, a lens, a cavity, a light sensitive membrane. That's an eye.
Nobody had to design it. It naturally arises in the conditions in which life existed/exists.
Quite readily replicated in generative network simulations.
*snicker*
In vivo != in vitro != ‘in silico’
“Why is the universe and Earth in particular so finely tuned”?
Because GOD is the mechanic!