Eye Floaters and Flashes of Light: Harmless or Needing Prompt Care

What it involves

MedlinePlus describes eye floaters as small specks, dots or lines that appear in front of the eyes but are actually inside them, made of bits of cell debris drifting in the vitreous fluid at the back of the eye. It says they are caused by age-related changes and are most visible against a clear sky or a white wall.

Who this is for

• Adults who notice specks, threads or cobwebs drifting across their vision
• Patients who see brief flashes of light in the side of their vision
• People who are very nearsighted or had cataract surgery and want to know their risk
• Anyone unsure whether new floaters mean they should be seen today

What to expect

• Questions about when the floaters or flashes began, whether they changed suddenly and whether any part of your vision is dimmed
• A review of your health history, including diabetes, high blood pressure and eye history
• Advice on whether you should see an eye doctor the same day or can schedule a routine exam
• A referral to an eye care professional, who does the dilated eye exam that looks for a retinal tear

What floaters are and why you see them

MedlinePlus says the floating specks are not on the surface of the eye but inside it, and that floaters may look like spots, specks, bubbles, threads or clumps. Most adults have at least a few. They tend to be most noticeable when reading, especially if a floater is dense or dark, and when looking at a plain bright background. Because they move with your eye, they seem to dart away when you try to look at them directly. For most people they are a nuisance that the brain learns to ignore.

The warning signs that change everything

MedlinePlus says floaters are most often harmless but can be a symptom of a tear in the retina. A sudden increase in floaters, or floaters together with flashes of light in the side of your vision, may signal a retinal tear or detachment, and it says to go to an eye doctor or emergency room. The National Eye Institute summary on its retinal detachment page adds that a curtain over the field of vision is another symptom, and calls detachment a medical emergency that can cause permanent vision loss if not treated promptly.

Who is more likely to have a detachment

The same National Eye Institute summary lists the people more likely to have a retinal detachment: those who are extremely nearsighted, who had a detachment in the other eye, who have a family history, who had cataract surgery, who have other eye diseases or who had an eye injury. It says detachment can occur at any age but is more common after 40. If any of those apply to you, mention it when you call, because it affects how quickly you should be seen.

What treatment looks like

MedlinePlus says floaters are difficult to eliminate. A vitrectomy can remove them but is a major eye operation that many doctors consider too risky for a minor problem. A laser treatment can break floaters up and possibly make them less visible without truly removing them, and atropine eye drops can make them less visible but may blur vision. It also notes that some homeopathic eye drops marketed for floaters have no proven benefit. None of this is done at a primary care office, so these are referral topics, and most people need nothing.

How a primary care visit helps

The dilated eye exam that looks for a retinal tear is done by an eye care professional, and a primary care provider will say so plainly. What the visit can do is sort the story: whether this is a long-standing speck or something new, whether vision is dimmed anywhere, and whether conditions such as diabetes or high blood pressure that affect the eye are under control. The blurry vision guide and the dry eye guide cover other eye symptoms that a primary care provider commonly sees.

What to do today if your vision changes

If you notice a sudden increase in floaters, flashes of light, a dark shadow or curtain across your vision, or sudden loss of sight in one eye, go to an eye doctor or emergency room that day rather than waiting for a routine appointment. Do not drive yourself if your vision is impaired. For floaters that have been present for a long time and have not changed, schedule a routine visit and mention them at your next eye exam.

Sources

• MedlinePlus: Eye floaters (medical encyclopedia)
• MedlinePlus: Retinal Detachment (health topic, National Eye Institute)