Eye floaters can be clumpy or stringy; light or dark. They are caused by clumps or specks of undissolved vitreous gel material floating in the dissolved gel-like fluid (vitreous) in the back of the eye, which cast shadows on the retina when light enters the eye.
Then, what causes floating spots in vision?
Eye floaters are spots in your vision. Most eye floaters are caused by age-related changes that occur as the jelly-like substance (vitreous) inside your eyes becomes more liquid. Microscopic fibers within the vitreous tend to clump and can cast tiny shadows on your retina. The shadows you see are called floaters.
On rare occasions, floaters can be so dense and numerous that they significantly affect vision. In these cases, a vitrectomy, a surgical procedure that removes floaters from the vitreous, may be needed. A vitrectomy removes the vitreous gel, along with its floating debris, from the eye.
Migraines. Migraine headaches can cause changes in vision, including seeing stars, sparkles, or flashes. They can also cause spots, heat-like waves, tunnel vision, or zigzagging lines. Retinal disturbances or decreased blood flow to the retina may cause these symptoms.
Move your eyes -- this shifts the fluid around. Look up and down, that usually works better than side to side. If you have so many that they block your vision, your eye doctor may suggest surgery called a vitrectomy. He'll remove the vitreous and replace it with a salt solution.
Flashes will almost always go away completely. It usually takes about a month, but sometimes it can take up to six months. Floaters will gradually get smaller and less noticeable as the weeks and months go by, but usually they never disappear completely. Do not worry if you have a few floaters.
Floaters caused by loose cells, for example, are usually not that bothersome and often go away on their own in a few weeks or months. The floaters that look like wispy threads tend to be more visible, and in most cases they will also go away with time. In some cases, however, they can signal other problems.
Retinal Tear. A tear in the retina can occur with vitreous detachment (see discussion above), with trauma or eye injury, or in areas at risk for a retinal tear, such as "lattice degeneration". The symptoms of a retinal tear usually are of a flash of light in the peripheral vision followed by floaters.
Rheum is made up of mucus, skin cells, oils and dust. The rheum that comes from the eyes and forms eye boogers is called gound, which you may know as eye sand, eye gunk, sleep dust, sleep sand, sleep in your eyes, or eye shnooters. When you're awake, gound doesn't cause any problems.
A sensation of flashing lights can be caused when the vitreous (the clear, jelly-like substance that fills the middle of the eye) shrinks and tugs on the retina. These flashes of light can appear off and on for several weeks or months. With age, it is more common to experience flashes.
Phosphenes are most commonly introduced by simply closing your eyes and rubbing them or squeezing them shut, tightly; generally the harder you rub or squeeze, the more phosphenes you'll see. This pressure stimulates the cells of the retina and, thus, makes your brain think you are seeing light.
The irregularity casts a shadow onto your retina, blocking small areas of your vision, which you perceive as floaters. Floaters occur naturally as the vitreous gel within your eye thickens or shrinks with age, causing clumps or strands to form. In most cases, floaters are completely harmless, if a little irritating.
Floaters and flashes are usually harmless and fade over time. This stirs the vitreous fluid in your eyes, moving floaters away from your line of vision. Flashes caused by the vitreous separating from the retina are a normal part of aging and should subside in a few weeks or months.
It happens when inflammation, vascular abnormalities, or injury cause fluid to build up under the retina. There is no hole, break, or tear. Tractional retinal detachment is when an injury, inflammation, or neovascularization causes the fibrovascular tissue to pull the sensory retina from the retinal pigment epithelium.
Phosphenes are the moving visual sensations of stars and patterns we see when we close our eyes. They are thought to be caused by the inherent electrical charges the retina produces even when it is in its “resting state” and not taking in a ton of information and light like it does when our eyes are open.
Flashes. When the vitreous gel inside your eye rubs or pulls on the retina, you may see what looks like flashing lights or lightening streaks. These flashes of light can appear off and on for several weeks or months. As we grow older, it is more common to experience flashes.
Benign eye floaters are tiny floating specks or cobwebs in your vision. Dry eye syndrome can cause pain, blurred vision, redness, light sensitivity, and often makes reading unpleasant. Long exposure to wind can cause painful skin, red skin, or dry skin.
Small arc-like momentary flashes of light in the peripheral vision are commonly experienced during vitreous separation. The vitreous pulls on the retina which makes one think they are seeing a light but it is caused by movement of the retina. Rarely flashes are associated with a tear in the retina.
That baseball that zoomed through your hands and slammed into your forehead forces your skull to snap back, which can cause it to smack against the front part of the brain. Then, when you fall and hit the back of your head against the ground, your occipital lobe continues downward and can hit your skull. Voila: stars.
The stars are in the sky both day and night. During the day our star, the Sun, makes our sky so bright that we cannot see the much dimmer stars. At night, when the sky is dark, the light of the stars can be seen.
Mechanical stimulation. The most common phosphenes are pressure phosphenes, caused by rubbing or applying pressure on or near the closed eyes. They have been known since antiquity, and described by the Greeks. The pressure mechanically stimulates the cells of the retina.
So whether there is light entering the eye or not, any stimulation of the retina will be translated into a light show by the brain. If you see stars or flashes after sneezing, it could be from a pressure on the eye itself, or from stimulation of the nerves that have to do with sight.