There are many reasons for “floaters” and “flashers” in your eyes. The trouble is telling the difference between ones that are harmless, and ones that can be a sign of something serious going on that requires a trip to the eye doctor.

What is a floater?

A floater in your line of vision is usually dark and threadlike in appearance. It will usually change position when you move your eye, particular up and down rather than from side to side.

What is a flasher?

A flasher is a type of visual disturbance which is usually associated with lights and colors. Some people “see stars” when they are hit. Flashers can appear in a range of shapes and colors.

Reasons for floaters and flashers

In many cases, these visual disturbances are related to the aging eye. When we are younger, the amount of vitreous fluid in the eyeball is large enough to keep the eye fairly “full”. However, as we age, it starts to diminish. When the vitreous fluid is great, it presses up against the iris, pupil and lens of the eye. When it thins, there is no longer as much pressure, and you can start to see shadows of the structures of the eye. For example, you might see a floater called a Weiss ring, which is you seeing the shadow of your lens. As long as you don’t lose peripheral, or side vision, the floaters should be harmless and you will usually get used to them.

In terms of the flashing lights, these can be a sign of issues with the retina at the back of the eye. It might be pulling away from its position, leading to a retinal tear or even a detached retina, which is a medical emergency. Most of the time, however, it will be the result of eye movement and is most noticeable if it is dark in the room.

If you notice any sudden changes in your level of floaters and flashers, call your eye doctor to ask for an emergency appointment. Better safe than sorry.