What are those floaty things in your eye Michael Mauser
Have you ever noticed something swimmingin your field of visioné It may look like a tiny wormor a transparent blob, and whenever you try to geta closer look, it disappears, only to reappearas soon as you shift your glance. But don't go rinsing out your eyes! What you are seeing is a common phenomenon known as a floater. The scientific name for these objectsis Muscae volitantes,
Latin for quot;flying flies,quot; and true to their name,they can be somewhat annoying. But they're not actually bugsor any kind of external objects at all. Rather, they exist inside your eyeball. Floaters may seem to be alive,since they move and change shape, but they are not alive. Floaters are tiny objectsthat cast shadows on the retina, the lightsensitive tissueat the back of your eye.
They might be bits of tissue, red blood cells, or clumps of protein. And because they're suspendedwithin the vitreous humor, the gellike liquidthat fills the inside of your eye, floaters drift alongwith your eye movements, and seem to bounce a littlewhen your eye stops. Floaters may be onlybarely distinguishable most of the time.
They become more visiblethe closer they are to the retina, just as holding your hand closerto a table with an overhead light will result in a moresharply defined shadow. And floaters are particularly noticeable when you are lookingat a uniform bright surface, like a blank computer screen, snow, or a clear sky,
where the consistency of the backgroundmakes them easier to distinguish. The brighter the light is,the more your pupil contracts. This has an effect similarto replacing a large diffuse light fixture with a single overhead light bulb, which also makesthe shadow appear clearer. There is another visual phenomenonthat looks similar to floaters but is in fact unrelated. If you've seen tiny dots of lightdarting about
when looking at a bright blue sky, you've experienced what is knownas the blue field entoptic phenomenon. In some ways,this is the opposite of seeing floaters. Here, you are not seeing shadows but little moving windowsletting light through to your retina. The windows are actually causedby white blood cells moving through the capillariesalong your retina's surface. These leukocytes can be so largethat they nearly fill a capillary
Why Shouldnt You Look at the Sun
Some people think there is a myth that staring at the Sun can make you go blind It isn't. If you look at the Sun for too long, it'll do all kind of damage to your eyeballs. Sir. Isaac Newton, legendary smart guy learned that the hard way. He actually would wait in a dark room, so his pupils were dilated, then used one eye to look at a reflection of the Sun in a mirror just to see if it would create some kind of cool after image in his vision when he looked away. Apparently he ended up seeing some lovely circles and colors
so he repeated the experiment two more times and then so called quot;Phantasmquot; of lights and colors stayed in his vision for months. His eyes did eventually go back to normal but he ended up with sunlight phobia Good move, Newton. But it wasn't the only one who ended up with vision problems because of the Sun. Giovanni Cassini, the 17th century astronomer who studied the Saturn, also complained of vision problems from observing the sun early in his career. Galileo must have experienced something similar because he took to study in the Sun by shining the light through a pinhole onto another surface.
And that is still one of the safest, simplest ways to observe the Sun. Sunlight is mostly dangerous because of all of the untraviolet radiation it has and just a bit of that UV light can hurt your eyes. For example, it can give you photokeratitis, which is basically a sunburn on your cornea, the outermost layer of your eye. It causes blisters, pain and inflammation. Nothing's that you want happening to your eyeballs. Luckily, like regular sunburns, it's usually temporary unless you get a really bad one. Unfortunately, the damage doesn't stop at the top layer.
Unlike your skin, your cornea is transparent and allows some of UV light, called UVA radiation to pass into other part your eye and it can damage each of them in different ways. After passing through your cornea, UVA light hits the lens which bends and focuses light. Over time, repeated UV damages to the lens can cause cataracts, invasive tissue growth that makes in vision cloudy and eventually blindness. Once it goes though your lens, which is also transparent, the UV light hits your retina, the structure at the back of your eye that transmits images to your brain.
Normally light stimulates the retina, which is basically a cluster of sensitive cells, to release signaling chemicals. So when those cells are overstimulated, like if you're looking directly at the Sun, they put out way too much of the stuff. The signaling chemicals can actually damage the surrounding tissues resulting in blurry, dark or even lost vision and that can be permanent. It's called solar retinopathy and it's probably what Newton got. After a while UV light also tends to permanently damage a smaller part, right in the middle of the retina called the macula.
Along with some other things, it's responsible for the detail you can see right in the center of your field of vision. When bright light makes the pupil's contract, any light that still enters the eye hits the macula. Over time that can lead to macular degeneration which causes blind spots in the center of the field of vision. Like cataracts, macular degenerations can come from UV damage over time since we live in a world lit by the sun, the most you can really do is to wear a UV rated sunglasses and avoid looking anything to bright. But also in general just never look directly at the Sun.