What are flashes?
Have you ever seen flashes of light, stars, or streaks that aren’t really there? A few of these flashes are seen by everyone from time to time. Usually you see them in one eye at a time. Flashes are often caused by the vitreous (the gel filling the inside of your eye) pulling on the retina (a membrane that lines the inside of your eye). The vitreous shrinks from the retina over time; as it shrinks, the vitreous may pull on the retina, causing you to see flashes.
Who gets flashes?
As you age or if you are nearsighted (have fuzzy distance vision), you are more likely to see flashes. Sometimes, flashes are signs of other eye problems that need care.
What are floaters?
Floaters are little "cobwebs" or specks that float about in your field of vision. They are small, dark, shadowy shapes that can look like spots, thread-like strands, or squiggly lines. They move as your eyes move and seem to dart away when you try to look at them directly. They do not follow your eye movements precisely, and usually drift when your eyes stop moving.
In most cases, floaters are part of the natural aging process and simply an annoyance. They can be distracting at first, but eventually tend to "settle" at the bottom of the eye, becoming less bothersome. They usually settle below the line of sight and do not go away completely. Most people have floaters and learn to ignore them; they are usually not noticed until they become numerous or more prominent. Floaters can become apparent when looking at something bright, such as white paper or a blue sky.
Floaters occur when the vitreous, a gel-like substance that fills about 80 percent of the eye and helps it maintain a round shape, slowly shrinks. As the vitreous shrinks, it becomes somewhat stringy, and the strands can cast tiny shadows on the retina. These are floaters.
Floaters are more likely to develop as we age and are more common in people who are very nearsighted, have diabetes, or who have had a cataract operation. There are other, more serious causes of floaters, including infection, inflammation (uveitis), hemorrhaging, retinal tears, and injury to the eye.
Sometimes a section of the vitreous pulls the fine fibers away from the retina all at once, rather than gradually, causing many new floaters to appear suddenly. This is called a vitreous detachment, which in most cases is not sight-threatening and requires no treatment. However, a sudden increase in floaters, possibly accompanied by light flashes or peripheral (side) vision loss, could indicate a retina detachment. A retinal detachment occurs when any part of the retina, the eye's light-sensitive tissue, is lifted or pulled from its normal position at the back wall of the eye. A retinal detachment is a serious condition and should always be considered an emergency. If left untreated, it can lead to permanent visual impairment within two or three days or even blindness in the eye. Those who experience a sudden increase in floaters, flashes of light in peripheral vision, or a loss of peripheral vision should have an eye care professional examine their eyes as soon as possible.
For people who have floaters that are simply annoying, no treatment is recommended. On rare occasions, floaters can be so dense and numerous that they significantly affect vision. In these cases, a vitrectomy, a surgical procedure that removes floaters from the vitreous, may be needed. A vitrectomy removes the vitreous gel, along with its floating debris, from the eye. The vitreous is replaced with a salt solution. Because the vitreous is mostly water, you will not notice any change between the salt solution and the original vitreous. This operation carries significant risks to sight because of possible complications, which include retinal detachment, retinal tears, and cataract. Most eye surgeons are reluctant to recommend this surgery unless the floaters seriously interfere with vision.
Who gets floaters?
The older you get, the more likely you’ll notice floaters. Floaters can also be caused by an eye injury or surgery. If floaters appear suddenly or greatly increase in number, they may be a sign of an eye problem that needs care. Small pieces of vitreous gel or other material may float inside your eye.
Are flashes and floaters serious?
Most often, seeing a few flashes and floaters is normal. Also, some people may notice them for a while after eye surgery. Most flashes and floaters require no treatment. But sometimes they can be signs of a serious eye problem. To find out, you may need an eye exam.
Who should get an exam?
See your eye doctor if you notice any of the following symptoms:
- You have never seen flashes or floaters before and all of a sudden you see a lot of them
- You've seen some flashes or floaters before, but you have a sudden increase in the number you see
- You've seen some flashes or floaters for a long time, but they now look different than they used to
- Flashes or floaters make it hard to do your normal tasks
What happens at an eye exam?
Your eye doctor can check your eyes to be sure the flashes or floaters are not signs of a more serious eye problem. At an exam, your doctor will:
- Ask you questions. Knowing about your health and your family history of eye problems helps you doctor learn if you’re likely to have eye problems.
- Test your vision.
- Examine your eyes. Your doctor may dilate your pupils and use special instruments to see inside your eyes.
When do flashes need treatment?
Flashes that appear all of a sudden or greatly increase in number may be a sign of a problem. They may be caused by the vitreous pulling too hard on the retina. This can make the retina tear or detach from the back of the eye. Rapid vision loss can result. Your eye doctor can find the cause of flashes and decide if treatment is needed.
A sudden increase in the number of floaters you see may be a sign of a tear in the retina or of some other eye problem. Over time, a tear can cause the retina to detach from the back of the eye. Your eye doctor can find out what is causing the floaters and suggest a treatment plan, if needed.
It’s up to you!
The older you get, the more flashes and floaters you may see. They are usually harmless. But if you suddenly notice more of them, it may be a sign of an eye problem that needs care. Get regular eye exams to be sure that your flashes and floaters are normal and to protect and preserve your vision.