Ask the ophthalmologist: What causes floaters in the eye?

UTSW
By Angeline L. Wang, M.D. Ophthalmology

If you’ve ever stared up at the big Texas sky or a large reflective surface and then had what appeared to be small spots, strings, or cobwebs drift across your field of vision, you’ve likely experienced the condition known as eye floaters.

These floaters don’t cause pain, they move around in the vision and may seem to come and go. They are also incredibly common. Most people will experience floaters at some point in their life.

But there are some instances in which floaters can indicate a more serious condition. So, let’s take a closer look at the phenomenon of eye floaters.

What’s happening in the eye when floaters appear?

Floaters are usually caused by little clumps of protein that are part of the vitreous gel in the back of the eye. As the clumps of protein move around in your eye, they cast a shadow on the retina and you’re able to see those shadows.

Floaters tend to increase with age as the vitreous changes, becoming more liquefied and moving around in the eye more.

Are floaters dangerous?

In most cases, floaters are nothing to be concerned about. If you experience a sudden increase in floaters, however, this could indicate a posterior vitreous detachment, where the vitreous gel separates from the underlying retina. This tends to occur after age 50 but can occur in younger people that are near-sighted or have other conditions. When we are born, the vitreous gel is firm and fills up the back part of the eye, where it is attached to the retina. Over time, as the gel liquefies, it also shrinks and begins to pull away from the retina. When the vitreous starts to peel away from the retina, this process is called a posterior vitreous detachment. Most of the time, this process occurs over a matter of weeks and causes no risk to the vision. If during this process, however, the vitreous gel pulls too hard on the retina, it can cause a retinal tear, which if left untreated can lead to a retinal detachment.

An injury to the eye can cause a posterior vitreous detachment to occur sooner than it otherwise would. While a few floaters that don’t change much over time can be normal, if a sudden increase in floaters is experienced, there could be a more serious problem, such as a retinal tear. In this case, it is important to be seen by an ophthalmologist for a dilated exam to rule out a retinal tear or other problems, such as bleeding or inflammation, which could indicate an underlying medical condition that would need to be further evaluated and treated.

Is there a difference between floaters and flashes?

Yes, floaters refer to spots moving around in the vision. Flashes refer to flashing lights or “lightning streaks” in the vision. When flashes occur in association with a posterior vitreous detachment, this increases the risk that the vitreous gel is tugging on the retina, which increases the risk of a retinal tear.

What is the recommended treatment for floaters?

Anybody who has a sudden increase in floaters, especially if accompanied by flashing lights, should be evaluated by an ophthalmologist for possible retinal tear or retinal detachment. This examination requires dilation of the pupils with thorough examination of the peripheral retina, where the tears usually occur. If a retinal tear is found, it can usually be treated in the office with laser therapy.

When floaters are mild and not associated with a retinal tear or other problems, no treatment is usually recommended. Most patients adapt to them, and they become less noticeable with time. If floaters are large and persistent, affecting overall quality of life, they can be removed with a microsurgical procedure called a pars plana vitrectomy.

If you or a loved one needs to see one of our ophthalmologists, call 214-645-2020 or request an appointment online.