What Are Eye Floaters?
If you've ever been aimlessly staring off into the distance and happened to notice something shadow-like drift across your field of view, you likely paused to wonder what it was, and what caused it to happen.
Those little visual anomalies are called floaters, and are incredibly common. In most cases they aren't anything to worry about, but in some rare situations they may indicate a serious medical emergency. Whether or not you should be concerned depends on any other symptoms that may be occurring at the same time, such as seeing sudden flashes of light.
Floaters are actually tiny pieces of tissue that have broken off from the interior of the eye and are freely drifting through its fluid filled center. When that tissue passes between the pupil and the retina, incoming light is blocked and a shadow is cast.
People are more likely to experience floaters as they age. What starts off as a thick, gel-like substance in the center of the eye slowly becomes less viscous over time. With less resistance, the small bits of tissue are able to move about more freely, resulting in a greater frequency in the appearance of floaters.
They may appear as small, blob-like shapes, or as long, narrow strings. Depending on how they interfere with incoming light, they may appear as dark shadows, or as bright high-lighted spots.
Often times a floater may pass through the eye but go completely unnoticed. This is likely because the background against which they appear is busy, complex, and full of motion. It's unlikely that a floater will catch a person's attention while watching an action movie at the theater, since there is so much visual stimulus for it to get lost in. However, staring at a blank wall or back drop allows the tiny distortions to show up much more visibly by contrast.
Once a floater is noticed, it can be almost impossible to follow it as it moves. This is because of the unique relationship that floaters have with the eyes. Nearly everything that a person looks at throughout their entire lives is completely unaffected by the action of observing. Watching a pot doesn't make it boil any faster, and nor does it make the clock go any slower.
But floaters, however, are affected. By twitching the eye, even slightly, in order to focus directly on the floater, the fluid inside the eye is stirred, causing the floater to move. Attempting to follow it more only results in more movements, and eventually it drifts out of sight completely.
Only in the off chance that it drifts right through the center of vision will you be able to get a somewhat clear image of the floater, and even then, it only lasts for a second or two. Unless the eyes stay completely motionless, locked in focus on a singular distant point, the fluid inside will perpetually be in motion, and so will the floaters suspended within.
As mentioned above, there are some rare circumstances under which the appearance of floaters can be a symptom of a serious medical emergency. One or two floaters at a time aren’t anything to be concerned with, but many of them appearing within a short period of time isn't normal. Also, the appearance of bright flashes of light along with floaters is also something to be concerned about. Should these symptoms occur, you should seek out medical attention immediately.
What may be happening in this type of situation is that the retina, the tissue in the back of the eye that senses light, may be detaching from the rest of the eye. This condition, referred to medically as post vitreous detachment, can sometimes be corrected if it's treated quickly enough. If it isn't, however, that drastic or total vision loss may occur in that eye.
Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 10 Apr 2018, Last modified: 17 Jul 2019