What Causes Eye Floaters?

iStock / Mark_Kuiken
iStock / Mark_Kuiken

Eye floaters — or muscae volitantes, Latin for “hovering flies" — are those tiny, oddly shaped objects that sometimes appear in your vision, most often when you’re looking at the sky on a sunny day. They look like spots, or a squishy little amoeba, and drift aimlessly around in your field of vision. Try to get a fix on one, though, and it seems to disappear.

Floaters aren’t just optical illusions. You’re really seeing them, and they’re actually in your eye, not just on it or in front of it. The weird little squiggles are pieces of the vitreous humor, the fluid that fills the eye, breaking off and then floating about in your eyeball.

A little gross, I know, but completely normal. The vitreous humor fills the gap between your retina and lens and helps maintain the round shape of your eye. It’s made up of water bound up in a little hyaluronic acid and collagen. When you’re young, it’s thick and gel-like, but as you age, the hyaluronic acid network breaks down and releases the trapped water molecules. As this happens, the core of the vitreous humor becomes more watery and little bits of undissolved gel break off and slowly drift around. When light passes through the eye, the shadows of these pieces are thrown up on your retina and you perceive them as floaters.

A Closer Look

Since floaters, well, float, their paths generally follow the motion of the eye. This makes looking right at them difficult, and when you shift your gaze towards them, they often move and stay at the edges. They don’t always float, though, and many of them will sink towards the bottom of the eyeball. To get a good look at them, just lie down looking up at a clear sky. Some of the floaters will settle near the fovea, a small area that sits at the back center of your eye and is responsible for your sharp central vision. The lack of movement and the even, textureless background makes it easy to scope them out and watch the blobs bob around a little.

For the most part, floaters are nothing to worry about — just a sign that you’re not a kid anymore. The sudden appearance of a lot of floaters combined with the onset of other eye weirdness — like flashes of light or blurriness or loss of peripheral vision — could indicate a problem, though. Sometimes, floaters are a symptom of the vitreous humor pulling away from the retina, a retinal tear, or the abnormal growth of blood vessels in the eye. If your floaters cross the line from curiosity to nuisance, it’s time to give the eye doctor a call.

Keep Your Cat Busy With a Board Game That Doubles as a Scratch Pad

Cheerble
Cheerble

No matter how much you love playing with your cat, waving a feather toy in front of its face can get monotonous after a while (for the both of you). To shake up playtime, the Cheerble three-in-one board game looks to provide your feline housemate with hours of hands-free entertainment.

Cheerble's board game, which is currently raising money on Kickstarter, is designed to keep even the most restless cats stimulated. The first component of the game is the electronic Cheerble ball, which rolls on its own when your cat touches it with their paw or nose—no remote control required. And on days when your cat is especially energetic, you can adjust the ball's settings to roll and bounce in a way that matches their stamina.

Cheerable cat toy on Kickstarter.
Cheerble

The Cheerble balls are meant to pair with the Cheerble game board, which consists of a box that has plenty of room for balls to roll around. The board is also covered on one side with a platform that has holes big enough for your cat to fit their paws through, so they can hunt the balls like a game of Whack-a-Mole. And if your cat ever loses interest in chasing the ball, the board also includes a built-in scratch pad and fluffy wand toy to slap around. A simplified version of the board game includes the scratch pad without the wand or hole maze, so you can tailor your purchase for your cat's interests.

Cheerble cat board game.
Cheerble

Since launching its campaign on Kickstarter on April 23, Cheerble has raised over $128,000, already blowing past its initial goal of $6416. You can back the Kickstarter today to claim a Cheerble product, with $32 getting you a ball and $58 getting you the board game. You can make your pledge here, with shipping estimated for July 2020.

At Mental Floss, we only write about the products we love and want to share with our readers, so all products are chosen independently by our editors. Mental Floss has affiliate relationships with certain retailers and may receive a percentage of any sale made from the links on this page. Prices and availability are accurate as of the time of publication.

Why Did Noon Used to Mean 3 p.m.?

3 p.m. is basically noon for people who wake up at 12 p.m.
3 p.m. is basically noon for people who wake up at 12 p.m.
Mckyartstudio/iStock via Getty Images

If you’re a late sleeper, you might find yourself thinking 12 p.m. seems way too early to be considered midday, and the word noon would much better describe, say, 3 p.m. It turns out that ancient Romans would have agreed with you, if only for etymological reasons.

As Reader’s Digest explains, the days in ancient Rome were split into four periods of three hours each. The first hour was at sunrise around 6 a.m.—called prime, for first—followed by 9 a.m. (terce, denoting the third hour), 12 p.m. (sext, for sixth), and 3 p.m. (none, for ninth).

According to Merriam-Webster, Middle and Old English borrowed the time-keeping tradition, along with the Latin word for ninth, which was changed to nōn and eventually noon. Though we’re not sure exactly when or why noon started referring to 12 p.m. instead of 3 p.m., it could have something to do with Christian prayer traditions. In the Bible, Jesus’s crucifixion is said to have taken place at the ninth hour, and that’s when worshippers partook in their second of three daily prayers; the others were in the morning and evening. It’s possible that hungry monks were behind noon’s gradual shift from 3 p.m. to 12 p.m.—since their daily fast didn’t end until after the midday prayer, they had a built-in motive for moving it earlier.

While we didn’t exactly stay true to the original Latin meaning of noon, there’s another important remnant of ancient Rome hiding in the way we tell time today. Romans referred to 12 p.m. as meridiem, for midday, and so do we. A.M. is an abbreviation for ante meridiem, or before midday, and P.M. means post meridiem, or after midday.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.