Before you panic about your floaters, know that the overwhelming majority of flashes/floaters in vision prove to be harmless. Annoying, certainly, but usually little more than that. However, flashes and floaters (either together or separately) are symptoms of some eye conditions and diseases, and for that reason we strongly encourage you to have yours assessed (especially if your flashes/floaters are new).
In rare cases, floaters are a symptom of a serious eye disease (such as diabetic retinopathy), a serious eye injury, or a tumour in the eye.
Flashes of light, on the other hand, are often symptoms of a physical change to the eye (such as a posterior vitreous detachment or retinal detachment).
For these reasons, we recommend that any new instance of light flashes or floaters be examined by an optometrist. The examination, which is painless and non-invasive (learn more about our eye exams), will determine whether or not the floaters/flashes are symptoms of a larger problem.
Causes – Flashes of light in your vision are caused by physical manipulation of the retina. This physical manipulation could come from a lot of things: sneezing, coughing, taking a hit to the head (ever heard of someone “seeing stars”?), etc.
The retina is responsible for receiving incoming stimulus (in the form of light) and sending that information to the brain. When manipulated physically, such as when you take a big hit on the ice, this stimulus results in sensory information being sent to the brain. However, since it is not actual light, the brain doesn’t really know what to do with it (so it displays it as a streak or fleck of light bouncing around in your vision).
Symptoms – Flashes present as specks/dots or streaks (almost like lightning bolts).
Causes – Your eye is filled with a gel-like substance called the vitreous. As we age, the vitreous begins to change composition- turning from a gel into something more liquid. Inside the vitreous is a protein called collagen which clumps together as the vitreous changes, resulting in the floaters that inhabit your vision.
Symptoms – Floaters may appear as dots, threads, squiggles, lines, ropes, and other small artifacts in your vision.
In most cases, floaters are no cause for alarm. However, if it suddenly appears to be “snowing” floaters, seek medical attention ASAP as you may be experiencing a medical emergency.