Floaters are dots or lines that you may sometimes see moving or floating in your field of vision. Most cases, floaters are usually degenerated clumps of vitreous gel which is the clear gel-like substance that fills the inside of the eye. Occasionally, floaters may be tiny clumps of cells inside the vitreous gel due to bleeding or inflammation within the eye. While you may get the feeling that these spots or lines are in front of your eye, in reality they are actually floating inside it. These clumps cast shadows on the retina – the layer of cells lining the back of the eye that senses light and allows you to see – giving you the impression of floating particles in your vision.
Flashes are the sensation of flashing lights or lightning streaks in your field of vision that occur when the vitreous gel inside your eye pulls on the retina, which is a light-sensitive tissue. This may often happen when you turn or move your eyes. They can be a small flash in just one spot, or it can be several flashes across a wider area of vision.
Vision with floaters
Vision with flashes
There is no known prevention for floaters and flashes which are usually age-related, and in most cases benign. Flashes usually diminish with time (over weeks to months), and floaters may reduce somewhat over time, but usually persist in the long-term. If you experience floaters and flashes in your eye, it is important to have your eyes examined and checked by an eye specialist to determine the cause, and exclude retinal tears, detachments, or other serious conditions.
When we are young, the clear gel-like vitreous in the eye is attached to the retina. As we age, at some point in our lives, the vitreous will usually degenerate and pull away from the retina, which is called a posterior vitreous detachment (PVD). Sometimes, this may be triggered by eye injuries or excessive eye rubbing. PVD can cause symptoms of floaters and flashes for a few weeks, but in most cases does not cause any major problems. However, in a small proportion of patients the degenerated vitreous can pull and tear which can cause bleeding into the eye (vitreous hemorrhage), or a retinal detachment. Such conditions are serious and can result in visual loss.
Floaters and flashes usually do not lead to serious complications. Only a small proportion of patients develop retinal tears or retinal detachment. Nevertheless, new floaters and flashes, especially if accompanied by some and visual field loss (a dark shadow blocking part of your vision), should be evaluated promptly by an ophthalmologist to exclude serious conditions such as retinal tears and retinal detachments, as these can lead to permanent vision loss. In such cases, timely treatment with a laser, or surgery in severe cases, can help to prevent blindness.
The most common cause of floaters and flashes due to vitreous gel degeneration and PVD does not require specific treatment. Although laser and vitrectomy surgery are technically possible, these procedures do not always remove all floaters, and have potential risks, and so are rarely performed. The effect of floaters can be minimised by wearing dark glasses when you are out in the bright sunlight or when you are looking at a brightly lit surface. Flashes usually diminish and stop over weeks to months.