The eye has long been one of the most popular and historically significant parts of the human body. It’s found it’s way into various art forms and spread across various cultures in many different ways.
Everyone has their own understanding of the eye. It has been described as the window to the soul, the monitor for the brain computer, and a person’s reality tunnel through which they see the world.
But the more curious side of the eye deals with its development over the lifespan of the human species.
Evolutionary biologists know that species must adapt properly to survive.
Eyes have always been one of the most important parts of any species. The ability to find food, avoid dangers, and live a comfortable life depends largely on one’s ability to sense the world around them. For humans, like many other species, vision is one of the more important senses for accomplishing this.
How did the human eye change throughout centuries and millennia? What caused it to become more developed?
To understand how the eye has evolved, you must look back to the earliest traces of the eye in complex organisms.
The Beginnings of the Eye
Eyes as complex organs capable of transmitting visual images to a brain first emerged in the Cambrian period. This is when most animal phyla appeared on the fossil record.
Also known as the Cambrian explosion, this period saw a huge increase in the rate of evolution. Single-celled organisms and more primitive forms of life may have used light for various purposes, but lifeforms began using it for visual navigation roughly 541 million years ago.
The eye evolved in various ways, both in the amount of information it was allowed to take in and the resulting perception it would produce in conjunction with the brain. Species begun depending more on their eyes to find food when it was scarce. They needed good vision to dodge larger predators during the evolution arms race.
When human beings first appeared on the earth roughly 200,000 years ago, their evolved brains and potential for grappling with their surroundings made their vision one of the most important aspects of their genetic makeup.
How Human Eyesight Has Changed
Like all parts of the body, the eye must be treated in a certain way to ensure it accomplishes its desired function and does not become subject to problems.
The human eye has improved throughout the years, and even significantly since the beginning of recorded history roughly 6,000 years ago. The ability of humans to create civilization and begin to create a world subject to historical significance itself shows that eyes had improved to a point that they could be depended on.
Better bodily health also helped improve vision. As human begins began to understand things like sanitation, they created housing to shield themselves from harmful UV rays, and they gained a better grasp of nutrition, eyesight improved.
People began to be able to see at longer distances, and to visualize greater levels of detail.
The natural evolution of the eye is a curious sight in its own right, as it shows how a complex organism can come together over time and become an evolutionary advantage for many species.
But the manmade technological advances created in the area of vision improvement have also had a significant impact on the eye.
How Glasses, Contacts, and Surgery Influence the Eye
While the eye has evolved significantly, certain genetic and environmental factors still leave people with impaired eyesight.
While some have trouble seeing at short or long distances, others struggle to see colors, or even at all. This means that corrective devices have seen a significant evolution as well, primarily since the beginning of the industrial revolution in the 1800s.
Not only have contact lenses been developed to help those who dislike the idea of wearing glasses, but surgical options now exist as well.
There are a number of visual issues that corrective lenses can fix, but surgery offers a person a new option. Using a laser, optical surgeons can correct visual problems for good or implant devices to restore partial vision.
The evolution of the human eye shows how amazing the human body is, and how an important organ like this can be an evolutionary advantage.