What Are Floaters and Flashes?

What are floaters?

Floaters look like small specks, dots, circles, lines or cobwebs in your field of vision. While they seem to be in front of your eye, they are floating inside. Floaters are tiny clumps of gel or cells inside the vitreous that fills your eye. What you see are the shadows these clumps cast on your retina.

You usually notice floaters when looking at something plain, like a blank wall or a blue sky.

As we age, our vitreous starts to thicken or shrink. Sometimes clumps or strands form in the vitreous. If the vitreous pulls away from the back of the eye, it is called posterior vitreous detachment. Floaters usually happen with posterior vitreous detachment. They are not serious, and they tend to fade or go away over time. Severe floaters can be removed by surgery, but this is seldom necessary.

You are more likely to get floaters if you:

• are nearsighted (you need glasses to see far away)
• have had surgery for cataracts
• have had inflammation (swelling) inside the eye

What are flashes?

Flashes can look like flashing lights or lightning streaks in your field of vision. Some people compare them to seeing “stars” after being hit on the head. You might see flashes on and off for weeks, or even months. Flashes happen when the vitreous rubs or pulls on your retina.

As people age, it is common to see flashes occasionally.

Flashes and migraines

Sometimes people have light flashes that look like jagged lines or heat waves. These can appear in one or both eyes and may last up to 20 minutes. This type of flash may be caused by a migraine. A migraine is a spasm of blood vessels in the brain.

When you get a headache after these flashes, it is called a “migraine headache.” But sometimes you only see the light flash without having a headache. This is called an “ophthalmic migraine” or “migraine without headache.”