Eye Floaters: What They Are, and What Causes Them
Thanks to a certain episode of Family Guy (season 5, episode 11 “The Tan Aquatic with Steve Zissou”), public awareness of eye floaters is at an all time high. Yes, Stewie Griffin’s ode to the proverbial “squiggly line in my eye fluid” is an accurate, albeit comedic, representation of floaters.
Eye floaters are chunks of a collagen by-product, fibrils, that float inside the normally clear vitreous humour. The vitreous humour is a gel-like substance that is 99% water and 1% solid elements.
What Causes Floaters?
In the vast majority of cases (98% according to the American National Health Service), the cause is related due to natural changes in the vitreous as a result of aging. Rarely, floaters can be indicative of a retinal tear or detachment.
Interestingly, when you see a floater you aren’t actually seeing the floater itself. Instead, you are seeing the shadow the floater casts onto your retina.
Are Floaters Harmful?
Floaters can be annoying, but generally speaking they are no cause for concern. Almost everyone will experience floaters throughout their lives.
However, a sudden and significant increase in eye floaters – and especially if joined by flashers – warrants immediate investigation from an Optometrist. This may be indicative of a developing eye disease, or an impending retinal tear or detachment.
Eye Flashes: What They Are, and What Causes Them
Where floaters are generally benign and of no cause for concern, flashers are the opposite. Any new instance of flashers warrants investigation by an Optometrist. Flashers, unlike floaters, are not common.
Flashers are flashes of light or specs of light that suddenly appear and disappear in our vision. When people take a hit to the head and are “seeing stars”, this is the effect they’re referencing.
What Causes Flashers?
Stimulation of the retina causes an electrical signal to be sent via the optic nerve to the brain. This electrical signal is then interpreted and displayed to us by the brain. In most cases, light is the stimulant that sets this chain of events in motion.
However, when the retina is physically stimulated, such as when it is pulled on by the vitreous, the same type of electrical signal is generated and sent to the brain. This stimulation is presented to us as the flashers that we see in our vision.
Are Flashers Harmful?
Unlike floaters, flashers are not a generally common phenomena. They are connected to various eye diseases and conditions, such as posterior vitreous detachments and retinal detachments.
Any new instance of flashers should be investigated by an Optometrist to ensure the wellbeing of the eye.