Flashes and Floaters
A very common reason for an eye consultation at The Eye Practice Optometrists is the sudden appearance of “Flashes and Floaters” in our vision. This requires a very prompt appointment for a complete retinal check using eye drops to dilate the pupils.
What do flashes and floaters look like?
Patients often describe flashes of light as being like fireworks or arcs of light in their peripheral vision.
Floaters on the other hand are often described as cobwebs, black spots, strings, spidery shapes or veils hanging over their vision.
While floaters are common, flashes and floaters together should always be investigated in case they are indicative of a retinal tear or detachment.
What causes ocular floaters?
Floaters are little bits of organic material – blood traces, membranes etc – that are literally floating inside your eye.
The eye is filled with a jelly-like substance called the vitreous and when you are younger it is firm. As you age, it becomes more fluid, in a process called liquefaction. It can also shrink and peels away from the retina as you age. When this occurs it is called a vitreous detachment. It usually happens during middle age, and to one eye at a time, although both are commonly effected over time.
What are the symptoms of floaters?
As the vitreous gel peels away from the retina, its membrane hangs in the fluid inside your eye and you can notice a cobweb or even a ring shaped floater in front of your vision. Floaters are particularly noticeable against a brightly lit area, such as a blue sky or the bedroom ceiling in the morning. Floaters can also be caused by disruptions to the retina at the back of your eye.
If the retina tears or detaches from the back of the eye, there is often some blood released into the vitreous and this can often be observed as a floater. In extreme cases, where the retina has detached, the floater may be so large that it obscures part or most of the vision – much like a curtain hanging down.
What causes ocular flashes?
When the vitreous detaches, it comes away easily from most parts of the retina but it is more firmly attached around where the optic nerve enters the eye and also at the very edges of the retina, right out at the periphery. As it pulls on the edge of the retina it can cause those classic arc-shaped flashes to appear.
The good news is that once your vitreous detaches, it no longer exerts any pull on the retina and the symptoms – and the risk of retinal detachment – disappear.
Unfortunately, in some cases as the vitreous detaches, it pulls part of the retina off with it and this requires urgent treatment. Flashes are generally present in any retinal detachment, even if there is no involvement from the vitreous. Ocular trauma and high myopia are other risk factors for retinal detachment. Retinal detachment is a true ocular emergency and requires urgent treatment to give you the best outcome.
There are other, less sinister causes of flashes including ocular migraine and phosphenes.
What do I do if I have flashes and floaters?
If you have flashes and floaters that have suddenly appeared, make an appointment to be seen urgently (within 24 hours) with your optometrist. If your regular optometrist is closed over the weekend and this is when your symptoms appear, see another optometrist, who may refer you to an ophthalmologist or eye hospital for further investigation.
Or, go straight to the Eye Hospital or the Accident and Emergency department of your local hospital to rule out the chance of having a sight-threatening retinal detachment. If your symptoms first occur at night, rest until the morning and then see your optometrist.
Of all people that experience these symptoms approximately 15% will have a retinal tear, which can lead to a retinal detachment. The other 85% will just need monitoring.
Certain people have a greater risk, especially if you are myopic or short-sighted, have a family history of retinal detachment or have had a significant trauma to the head or to the eye.
What will my eye care expert do if I have flashes and floaters?
Your vision will be assessed, including your peripheral vision and a thorough examination of your retina will be performed. Dilating eye drops are used to open your pupil so the retina can be examined more easily. Depending on the findings, you may be given the all clear or referred to a retinal specialist.
If your retina has torn or detached, a retinal specialist will treat it urgently to reattach it before it comes away even further from the back of your eye.
What happens if I have a retinal detachment?
Retinal detachment is very successfully treated if discovered early. Some retinal tears cause no symptoms and require no treatment. Others have the potential to cause permanent blindness if large part of the retina detaches.