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Flashes and Floaters

What it Looks Like to See Flashes and Floaters

What is a Posterior Vitreous Detachment?

A clear, jelly-like substance called the vitreous fills 80% of the inside of the eye, in the space behind the iris and lens. The vitreous fills the space behind the iris and lens. It lies between the lens and the retina.

It is typically tightly attached to the retina. As we age, the vitreous becomes more liquid-like and separates from the retina near the back of the eye, over the macula. This separation is called a posterior vitreous detachment, or PVD. A PVD naturally occurs in 40% of people by age 40 and nearly 70% by age 70; however, it can occur in younger nearsighted patients or after an eye injury or surgery. As the vitreous separates from the retina one will often see floaters.

Most floaters and flashes will subside over time. Most patients’ symptoms fade over weeks to months, but some will occasionally notice the floaters indefinitely.

Chart Illustrating How Flashes and Floaters Appear in an Eye

The jelly-like fluid in the posterior chamber, called the vitreous, is surrounded by a very thin membrane. The fluid also contains many fibers that are usually invisible. This whole structure is called the vitreous body.

Sometimes the fibers in the vitreous body pull loose from where they are normally attached. When this happens, they can make cast shadows inside the eye.

Very rarely, a floater turns out to be blood tugging on the blood vessels. This could be caused by an injury or by systemic conditions that the patient may have. When there is bleeding, there is a greater danger of losing vision.

More often, floaters are caused by a posterior vitreous detachment. This occurs when the jelly-like fluid in the eye liquefies with age.


Eye floaters are small moving spots or specks that appear in your field of vision. They may be especially noticeable when you look at something bright, or go outdoors. Blinking does not get rid of the specks or threads. And these specks move with eye movement. These are called floaters.

There are a few different types of floaters, and each has its own cause. In general, though, eyes that are injured, inflamed, or nearsighted (cannot see objects far away) are more likely to get floaters.

There is no way of knowing the cause of floaters without a careful examination. This is why it is important for anyone who starts seeing floaters to schedule an appointment with their eye doctor as soon as possible.

Most of the time, floaters are not the sign of anything dangerous. Floaters caused by loose cells, for example, are usually not that bothersome and often go away on their own in a few weeks or months. If the floaters are caused by blood, this can be a sign of a more serious problem.

Only after a careful examination can your doctor give advice about possible treatment for floaters. In many cases, the examination will confirm that the floaters are not a symptom of a more dangerous condition. The doctor might just recommend that the patient have eye examinations more frequently to make sure that the eye with floaters does not get any of the more serious conditions later.


Sometimes when vitreous body fibers pull on the retinal nerve cells, the eye has the sensation of a flash of light. This can be a small flash in just one spot, or it can be several flashes across a wider area of vision. It is not unusual for flashes and floaters to occur at the same time.

Flashes can be a symptom of a retinal detachment, which can damage vision significantly. Anyone who experiences flashes should see their eye doctor as soon as possible. If the flashes have been caused by a retinal detachment, the doctor will be able to give advice on possible treatment options.

What is a Retinal Detachment?

The vitreous can pull on the retina as it separates, stimulating the retina, which is perceived as flashes of light. If the vitreous rips the retina, this retinal tear will allow liquid vitreous to fall behind the retina. As the fluid falls behind the retina, the retina separates from the back of the eye. The retina begins to lose its function and this is perceived as a curtain or veil over the vision. This is called a retinal detachment.

Your doctor will try to find the retinal tear before a retinal detachment develops. The examination involves dilating the pupil and looking at the vitreous and retina.

Signs and Symptoms of a Retinal Detachment

The symptoms described above may not necessarily mean that you have a detached retina. However, if you experience one or more of these symptoms, contact our office for a complete exam.