5. Motion-Induced Blindness
The human eye is like a camera with a slow shutter. As a result, moving objects sometimes trail streaks across our vision. The brain’s attempt to protect us from annoying streamers led to something called motion-induced blindness. For the most part, this phenomenon erases the lines. But it also causes stationary objects behind the moving ones to vanish. One minute the fire hydrant is there but as a car passes at night (here the brain wipes the tail light streamers), the hydrant is gone.
This striking illusion is not a sign that our vision suffers from a serious glitch. As a species, humans evolved to notice moving things. Predators and prey had to be seen in order to survive and neither stood still. For this reason, scientists believe that motion-induced blindness helps to see whatever is moving with clarity, rubbing out the streaks that interfere with perception while also blotting out the things that do not move—nor matter—at that moment.
4. The Surprise Discovery Of BARM
When researchers in Germany tested a group of volunteers, they pretty much expected the results to confirm an old suspicion. The study aimed to conclusively prove the link between blinking and tOKN. The latter is an automatic reflex and a well-known feature of the eye. Supposedly, it resets the eye muscles when a person gazes at a rotating object. This prevents the muscles from twisting past their limits.
The 2016 study stumbled upon something unexpected—a completely unknown eye movement was resetting the muscles. Since it happened automatically with each blink, the feature was called blink-associated resetting movement (BARM). The link with tOKN was confirmed but that was also how BARM turned up.
As the volunteers gazed at rotating stuff, tOKN frequently occurred but the movement lacked efficiency. The muscles eventually twisted to the maximum limit of between three and eight degrees of rotation. At that point, BARM suddenly kicked in and completely untwisted the eye’s muscles.
3. There Are People Who See Calendars
We all see calendars. One just needs to look at the wall and there it is. A roughly square-shaped paper filled with blocks and dates. But a small percentage of the population—around 1 percent—can see an almanac in their mind’s eye. Where the rest of humanity must look at an outside source these individuals see a vivid grid without assistance. In fact, they can see the dates and days far into the future.
This ability is called “calendar synaesthesia.” To listen to people describe how they experience this ability is spell-binding. One woman saw the months stretch before her in a V-shaped formation. Another’s calendar appeared as a large ring and no matter the time of year, December was always passing through her body.
Both women cemented scientific conviction that the phenomenon was not just seeing an imaginary image. In 2016, both went against the scientists’ best attempts to ruin anything that could be a mental image. If they really were seeing the calendars, their ability would survive. Not only did the pair come through with flying colors but their tests provided the first direct evidence that calendar synaesthesia is not rooted in the mind, but in the brain. Just like other synaesthetes, who can taste words or hear colors, their brains stimulated several sensory and neurological pathways to produce a tangible outcome—in this case seeing a real calendar.
2. We See Infrared Light
Open any science textbook and it will tell you that humans cannot see certain wavelengths. These include radio waves, X-rays, ultraviolet and infrared light. As it turns out, the books are outdated. In 2014, it became clear that people can detect infrared light.
Scientists were alerted to the fact after several of their colleagues reported seeing green flashes while working with infrared lasers. These look nothing like the lasers in action movies or pointers in boardrooms. Infrared lasers are supposed to be invisible.
In order to unravel the surprising possibility of seeing things in the invisible spectrum, an international team descended upon the eye cells of mice and humans. During the tests that followed, they zapped different parts with pulses of infrared light. The results showed something incredible. The human retina detects this wavelength when hit with a particularly strong dose of infrared energy. The concentrated light particles lengthen the retina’s visual spectrum and this allows the human eye to temporarily see into the invisible range.
1. The Eye Sees Patterns The Brain Cannot Detect
At first blush, one would think that the eyeball can never be better than the brain. After all, eyes exist only to see while gray matter has many abilities. However, our blinkers beat the brain in one way and it surprised even the experts.
Enter ghost images. These pictures are encoded as random patterns in other images. Only computers had the ability to pick up on their presence—or so everyone thought. In 2018, the complicated calculations required to identify the ghost images turned up in the human eye. Where the brain fails to see these individual patterns, the eye detects them, gathers the information and sums everything up.
This might not sound so incredible until you realize the complicated nature of ghost images. Making one is similar to taking a photograph in reverse. A laser then hits and “reads” multiple spots on the surface to reconstruct the image. Similarly, the eye registers the light points bouncing off a ghost image and use them to pull a picture together.