Original photo by Andriiii/ Shutterstock
Your eyes are how you see the world, but they’re also how you see yourself — including inside of your own eye. You may have experienced this while having your eyes examined, such as when the doctor shines a light on your pupils. When light comes from a small point and hits your eye just right, you can see your own blood cells as they move through the capillaries on your retina. The light reflects off the vessels, casting a shadow onto the light-sensitive cells in the retina and rendering them visible to your brain in a pattern of orange or red coloration. Each heartbeat sends those blood cells surging, adding a rhythmic quality to this strange phenomenon.
Oops, incorrect!
It's a factThe orbicularis oculi, the muscle that controls the eyelids, is indeed faster than any other muscle. Each eye contains one, which closes and opens the eye in less than 100 milliseconds.
You may also have experienced what’s called the blue field entoptic phenomenon while staring at the clear blue sky and noticing clear, floating cells moving through your field of vision. Unlike red blood cells, white blood cells don’t absorb the short wavelength of the blue light, allowing you to see them as they flow through the blood vessels in front of the retina. These are different from floaters (small spots that move through your field of vision), which tend to increase with age as the vitreous fluid in your eye changes thickness. In most cases, floaters are a normal aspect of aging, though in excess they could be a sign that you should have your eyes checked.
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The rarest of the main eye colors is ______.
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The rarest of the main eye colors is green.
Owls don't have eyeballs.
There’s a good reason owls can crane their neck so well: They can’t move their eyes. That’s because they don’t actually have eyeballs but rather eye tubes or cylinders that are fixed in place and only allow them to look straight ahead. As countless field mice can attest, their vision doesn’t exactly suffer from this lack of movement. Owls’ binocular vision allows them to see with both eyes at the same time, a relatively rare trait shared by humans, snakes, wolves, and other predators. Their field of vision is roughly 110 degrees, 70 degrees of which are binocular; humans, by contrast, have a visual field of 180 degrees, with 140 degrees being binocular.
Michael Nordine is a writer and editor living in Denver. A native Angeleno, he has two cats and wishes he had more.
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