Dark Spot In Left Eye Vision

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

Vision Crash Course AP 18

Take a good long look at this we're gonna mess with your brain. This is the first stage of an optical illusion. Many illusions use patterns of light or perspectiveto exploit the disconnect that exists between sensation and perception between what youreyes see and what your brain understands. But not all illusions work that way. Someproduce ghost effects, or afterimages, that take advantage of glitches in the physiologyof human vision. Like this flag. I'm not trying to make a political statementhere. And I'm not going ask you to swear

allegiance to the Republic of Hank or anything.I mean, if I was gonna start my own country, my flag would be way cooler than that notthat I've thought about that a lot. And now, look at this white screen. If you looked at that flag for at least 30seconds without moving your eyes, you'll see something, even though this screen isblank an afterimage of the flag. But instead of being turquoise, and black, and yellow,it's red, white, and blue. OK so that's pretty cool, but I'm nothere just to entertain you. This kind of illusion is actually a great way to explain your verycomplex sense of vision.

And I do mean complex… nearly 70 percentof all the sensory receptors in your whole body are in the eyes! Not only that, but in order for you to see,perceive, and recognize something whether it's a flag or a handsome guy in glassesand a sport coat sitting behind a desk nearly half of your entire cerebral cortex has toget involved. Vision is considered the dominant sense ofhumans and while we can get along without it and it can be tricked, what you are aboutto learn is NOT an illusion. When we talked about your sense of hearing,we began with the mechanics of sound. So before

we get to how your eyeballs work, it makessense to talk about what they're actually seeing light bouncing off of stuff. Light is electromagnetic radiation travelingin waves. Remember how the pitch and loudness of a sound isdetermined by the frequency and amplitude of its waveé Well, it's kind of similar with light, exceptthat the frequency of a light wave determines its hue, while the amplitude relates to itsbrightness. We register short waves at high frequenciesas bluish colors, while long, low frequencies look reddish to us.

Meanwhile, that red might appear dull andmuted if the wave is moving at a lower amplitude, but super bright if the wave has greater amplitudeand thus higher intensity. But the visible light we're able to seeis only a tiny chunk of the full electromagnetic spectrum, which ranges from short gamma andX rays all the way to long radio waves. Just as the ear's mechanoreceptors or thetongue's chemoreceptors convert sounds and chemicals into action potentials, so too doyour eyes' photoreceptors convert light energy into nerve impulses that the braincan understand. To figure out how all this works, let'sstart with understanding some eye anatomy.

Some of the first things you'll notice aroundyour average pair of eyes are all the outer accessories like the eyebrows that help keepthe sweat away if you forgot your headband at raquetball, and the supersensitive eyelashesthat trigger reflexive blinking, like if you're on a sandy beach in a windstorm. These features, along with the eyelids andtearproducing lacrimal apparatus are there to help protect your fragile eyeballs. The eyeball itself is irregularly spherical,with an adult diameter of about 2.5 centimeters. It's essentially hollow full of fluidsthat help it keep its shape and you can

Leave a Reply