Flashes of light are brief, flash-like light phenomena at the edge of your field of vision, while floaters appear as small moving dots, threads or streaks. They usually result from age-related changes in the vitreous body inside the eye and are often harmless. However, it is important to take newly occurring or rapidly changing phenomena seriously, as they may affect the retina.
Possible causes
Vitreous opacities
Small condensations in the jelly-like vitreous body cast shadows on the retina and appear as moving dots or threads.
Posterior vitreous detachment
With age, the vitreous body separates from the retina, which can trigger flashes of light and increased floaters.
Traction on the retina
When the vitreous body pulls on the retina, flashes of light occur; this should be examined by an ophthalmologist to assess the retina.
Short-sightedness
Severely short-sighted eyes are more prone to vitreous changes and therefore to floaters.
Typical steps at the doctor's office
- 1The ophthalmologist asks how long the phenomena have been present, whether they have suddenly increased, and whether a shadow has appeared in the field of vision.
- 2After dilating the pupil, she examines the vitreous body and the entire retina, including the peripheral areas, to rule out tears or a detachment.
- 3Unchanged floaters do not need treatment; a retinal tear is usually secured the same day with laser or cold treatment (cryotherapy), while a detachment is treated surgically.
What you can do yourself
- Stay calm if individual floaters have been present for a longer time without change and your vision is otherwise good.
- In good lighting and against a bright background, consciously watch for changes.
- Give your eyes rest and avoid focusing on the spots.
- If you have known short-sightedness, have your eyes examined regularly.
New flashes of light, a sudden increase in additional floaters, or a shadow at the edge of the field of vision should be examined promptly by an ophthalmologist in order to assess the retina. Even in the case of known severe short-sightedness, a prompt check-up makes sense. Long-standing, unchanged spots, on the other hand, usually have no disease value.
Frequently asked questions
- Are floaters dangerous?
- Individual floaters that have remained unchanged for a longer period of time are usually harmless and a normal ageing process of the vitreous body. However, if they suddenly increase in number or occur together with flashes of light, the retina should be examined by an ophthalmologist the same day.
- Why do I see the spots particularly against a bright background?
- Against bright, uniform surfaces such as a white wall or the sky, the shadows of the vitreous opacities stand out more clearly. This makes the floaters more visible, but does not mean they are increasing.
- Do floaters disappear again?
- Often the brain becomes less consciously aware of them over time, and some sink out of the central field of vision. They usually do not disappear completely. If they suddenly increase, an examination is important.
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