We often take our eyes for granted. Humans are highly visual creatures, so try to take a moment to give thanks for your good eyesight. Truly, our bodies are magnificent, and one of the most interesting and critical parts is the eye. Whatever feelings and thoughts you experience while reading this article at this particular moment are directly a result of photons of light being processed by the eyes and relayed to be interpreted by the brain.
The following are five fascinating facts about your eyes.
1. Eye Cells
Over 120 million cells extremely sensitive to light make up the retina in the back of your eyes. About 6 to 7 million of these cells are “cones” and it’s these cones that allow you to see colours and other details of your surroundings. The remaining 110+ million cells are known as “rods”. These rods enable you to see better in the dark and differentiate between black and white. Surprisingly, only about less than a ten percent of our visual receptors can detect colour.
2. Blinking
On average, a person blinks about 17 times per minute, which is 28,800 times per day, and 5.2 million times a year. When reading, you actually blink less which is the reason your eyes can feel weak and tired very quickly when you’re spending lots of time reading or working on the computer.
Invariably, you blink more while chatting. The old saying, “In the blink of an eye” came about as a result of the fact that the muscle that enables you to blink is the fastest muscle in the body. Scientifically, a blink lasts 100-150 milliseconds, and this blink is necessary for keeping your eyes moist and debris-free.
3. Focus
The focusing object in the eye which is the lens is faster than any man-made camera. These changes occur even before you even realize what is happening. If it was like most cameras and took a second or two, things would continue to seem out of focus.
4. Vision
Your eyes consist of over 2 million different parts that work together to create the vision. Doctors are yet to able to transplant eyeballs from one human to another as a result of the sensitive nature of the optic nerve. Surprisingly, the corneas of a shark are quite similar to that of humans and research is being carried out to determine if they can be used successfully in human eye transplantation.
5. Eye Colour
The level of melanin in your iris controls eye colour. Brown eyes contain more melanin (a dark pigment in the iris), while blue eyes have less. This enables blue collagen to show through. It is interesting enough to note that if you have blue eyes, you share a common ancestor with every other blue-eyed individual on earth. The first ever blue-eyed person lived sometime between 6,000 and 10,000 years ago. Before him, everybody had brown eyes.
These are just some of the amazing facts there are about the eyes which should give you enough reason to be thankful for them.