Seeing Specks or Flashes of Light? Here's Why

Dr Goh Kong Yong, an ophthalmologist at Mount Elizabeth Novena Hospital, explains what floaters and flashes are and how they can affect your vision.

What are floaters and flashes?

Often described as looking like 'flies', 'cobwebs' or 'dots', you may sometimes see floaters in your field of vision. Like the name suggests, these tiny specks float about like dust as you move your eyes. These floaters are more obvious when you see them against a bright sky or a white screen on the computer.

What causes flashes in the eyes?

When the vitreous gel inside your eye moves and pulls on the retina, this sets off an impulse seen as a flash. They can last for a few seconds or a few minutes.

They may appear on and off for several weeks or months, and are generally more obvious in dim areas. As you age, the vitreous gel liquefies, which is why you might start seeing flashes of light.

What causes floaters in the eyes?

Floaters are tiny clumps of cells inside the vitreous (a jelly-like fluid) that fills the inside of the eye. They form as the vitreous gel degenerates, which is part of the normal ageing process. As these cells float in the vitreous gel, they cast shadows on the retina, causing us to see floaters.

More rarely, these floaters are caused by blood or inflammatory cells. This is more common in people with diabetes or who already have an inflammatory condition of the eye.

As you age, the vitreous gel liquefies, which is why you might start seeing flashes of light. With each eye movement, the vitreous gel moves and pulls on the retina, setting off an impulse seen as a flash.

Can I do anything to prevent floaters and flashes?

Currently, you can't do anything to prevent or remove floaters and flashes. However, they usually become less obvious with time.

Should I be worried about eye floaters?

Floaters and flashes are very common. Luckily, they are usually harmless, but you may find them a bit irritating.

Floaters and flashes are only a matter of concern if the vitreous pulls on the retina and tears it. Subsequent bleeding may appear as an intense 'shower' of new floaters. If left untreated, a retinal tear can cause the retina to fully detach from the eye, which may lead to blindness.

If you experience a sudden appearance or increase of floaters in the eyes, consult an eye doctor immediately to rule out a tear, or to get timely laser surgery to repair it.

If you see a dark or translucent 'curtain' across your eye after sudden floaters and flashes, this may indicate that your retina has detached.

In rare cases, eye floaters may cause vision impairment. If this happens, you can discuss treatment options with your ophthalmologist. A possible option is to undergo a YAG laser vitreolysis which uses a specialised laser to break up the floaters in the vitreous jelly into smaller less noticeable ones. The outcome is variable as some patients benefit from the procedure whilst some do not. Another option is to remove the vitreous through a surgical procedure called vitrectomy. As this is a surgical procedure it is best that you discuss the procedure with your eye surgeon.

If you experience these symptoms, seek medical advice immediately to lower your risk of any permanent damage. And remember: an annual eye check-up by an eye specialist is vital to maintain your eye health, especially if you are short-sighted. Like with all health issues, intervening early gives you the best chance of recovery!