No lens - no image of this universe

[nycpaull]

My science reading includes the physics and chemistry of the brain. In reading about the process that collects light energy bouncing around the universe, focuses it and delivers it to our brains via chemical and electrical signals makes me realize that the "images" of the universe we take for granted on APOD are rare around the universe. The ability to create or see images of our universe rather than just sense waves of energy is amazing to contemplate. I guess we can assume that on a planet somewhere there is a transparent globule of liquid that focuses its surroundings or a pin point hole in a frozen lava mass that projects an image. I wonder how alien creatures without a focusing sense would "see" their surroundings and how did the first animal lens evolved. All this is to say that I really love focusing on APOD pics that passed through a few lens on their way to me. It's so easy to take our sight for granted.

[geckzilla]

You can create a model to see what kind of image would be received by photoreceptive cells. There are many variations right here on Earth to study which can give you an idea about how eyes could possibly evolve in alien species. There is a nice Wikipedia article on the evolution of the eye.

https://en.wikipedia.org/wiki/Evolution_of_the_eye

[Ron-Astro Pharmacist]

It's curious that the evolution of the eye appears to follow the embryogenesis of eye. Our DNA could be like a time machine in that way. Recapitulation theory is controversial but interesting.