The eyes are an infinitely fascinating and incredibly remarkable part of the human body. The eyes are the organ we use to see and interpret the world around us. They have been called the ‘windows to the soul’ and are not only one of our most important organs but also one (if not the) most expressive part of our anatomy. In essence the eyes say so much about us without in fact saying anything at all. Because of technological advances in the field of optometry and ophthalmology, we now know more about the eyes than ever before. Here are our top 10 interesting and informative facts you (probably) didn’t know about your eyes.
A BLINKING LONG TIME
Scientists have shown that a person blinks on average 10-15 times a minute, each blink lasting for 100-150 milliseconds. This is so frequent that our eyes are closed for roughly 10% of our waking hours.
A DIFFERENT POINT OF HUE
Men’s eyes are less adept at distinguishing shades in the centre of the colour spectrum. This means that men require longer wavelengths to perceive the same colour hues as women.
BEHIND BLUE EYES
People with blue eyes are all descended from a single common ancestor. The first blue-eyed person existed between 6,000-10,000 years ago in the Black Sea area in Southeastern Europe. Before that individual’s genes mutated to create blue eyes, everyone had brown eyes. Blue eyes have less melanin, which allows the blue colour of collagen to show through.
FLOATERS
The small dots seen floating in your vision when you close your eyes are optical debris such as dead cells, floating in your visual field. Floaters are most often caused by the normal aging process of your eyes and will usually disappear as your brain learns to ignore them.
EYELASH MITES
About half the population have microscopic mites called demodex living in their eyelashes. The likelihood of you having these little critters in your lashes increases as you get older, so that by the age of 60 it’s 80% likely you have them. The demodex mite feeds off oils and dead skin cells in your lashes; they are completely harmless.
SEEING WITH YOUR BRAIN
The role of our eyes is to gather all the information about an object and then send all this information to the visual cortex (the brain’s sight department). The brain then assembles all this information to produce the image that we identify.
EVOLUTIONARY AFTER-EFFECTS
Located at the inside corner of your eye is pink skin, which is the remnant of the nictitating membrane. This was a third eyelid that would draw across the eye for protection, and is present in other animals such as birds, reptiles, and fish. It’s one of many evolutionary traits discontinued by mammals.
THE RIGHT WAY UP
If you were to wear glasses that flipped the image you see upside down, your brain, after a few days, would correct that to the right way up.
SEEING RED (OR NOT)
Although your retinas have red, green and blue colour receptors, the ‘red’ receptor only detects yellow-green, and the ‘green’ receptor detects blue-green. Your brain combines these signals for you see the colour red.
STANDARD VISION
20/20 vision is ‘normal’, not perfect, vision. Optometrists have determined what people should normally be able read on a chart from 20 feet away, so having 20/20 vision just means you can see 20 feet in front of you as well as the average person can.
One thing you do already know is this – your eyes are extremely valuable to you. That’s why it’s so important to get your eyes checked on a regular basis. Not only will this help you maintain optimal eye health and visual capability, but regular checkups help detect potential vision problems and correct them before they get worse.