The birth of vision

The following is an epic tale, an epic tale that took place nearly 540 million years ago.

Around this time, on the pale blue cosmic dot that would later become known as Earth, life was quite tranquil and hassle-free. Back then, almost all of our ancestors were water dwellers, who would just float about in the serenity of the oceans, munching on sources of food only if they were to float by them. Yes, this was quite different than the predatory, stressful, and stimulating world of today.

Suddenly, something quite curious occurred. In a comparatively short period of time that followed, there was an explosion in the number and variety of animal species present on our planet. In only a span of about 20 million years that came after, the kind of creatures you could find on our watery earth drastically changed. They changed from the occasional single-celled organisms you would encounter, organized in loosely connected colonies, to complex multi-cellular organisms, popping up in every creek and corner.

Biologists remained baffled for a very long time, debating what caused this big bang of evolutionary acceleration. What we had actually discovered was the birth of the biological visual system. Studying the fossil records of the organisms from that time, zoologists were able to present decisive proof, connecting this explosion of species with the first appearance of photo-receptive cells. These cells allowed organisms to sense and respond to light, triggering an evolutionary arms race that eventually led to the sophisticated mammalian visual cortex that you are likely using right now to interpret this piece of text. Indeed, the gift of sight made life much more dynamic and proactive, as now organisms were able to sense and respond to their environments.

Today, vision is one of the main sensory systems in nearly all organisms, intelligent or not. In fact, we humans use almost half of our neuronal capacity for visual processing, making it the biggest sensory system we employ to orient ourselves, recognize people and objects, and go about our daily lives. As it turns out, vision is a very important component of cognitive systems, biological or otherwise. Hence, it is quite reasonable to go about examining the development and implementation of visual systems created by nature. After all, there's no point reinventing the wheel.