Floaters and Flashing Lights

Floaters are small spots, specks, strands, or cobweb-like shapes that drift across your field of vision. They're caused by tiny clumps in the vitreous, the gel-like substance filling the eye. While usually harmless, sudden changes in floaters, especially with flashing lights, can indicate a serious condition requiring immediate attention.

What Floaters Look Like

People describe floaters as:

• Small dots or specks
• Squiggly lines
• Cobwebs
• Ring shapes
• Thread-like strands

Characteristics:

• Move when you move your eyes
• Drift away when you try to look directly at them
• More noticeable against bright backgrounds (blue sky, white wall)
• Usually in one eye (though both eyes can have them)

What Causes Floaters

Age-Related Changes (Most Common)

Posterior Vitreous Detachment (PVD):

• Vitreous gel shrinks and pulls away from retina with age
• Very common after age 50 (occurs in most people by age 70)
• Causes sudden onset of floaters and flashes
• Usually harmless but requires examination to rule out retinal tear

Vitreous Syneresis:

• Gradual liquefaction of vitreous gel
• Creates strands and clumps that cast shadows

Other Causes

• Retinal tear or detachment—serious, requires immediate treatment
• Vitreous hemorrhage—bleeding into the vitreous
• Inflammation (uveitis)
• Eye surgery or trauma
• Diabetic retinopathy
• Nearsightedness (myopia)—higher risk of earlier PVD

Flashing Lights

What They Mean

Flashing lights (photopsia) occur when the vitreous pulls on or stimulates the retina:

• Often described as lightning streaks or flickering lights
• Usually in peripheral vision
• More noticeable in dark environments
• May occur with eye movement

When Flashes Occur

• PVD—common with new floaters
• Retinal tear—warning sign
• Migraine aura—different pattern (usually zig-zag, both eyes, with headache)
• Posterior vitreous separation

Retinal Tear and Detachment

Why It's Serious

When the vitreous pulls away from the retina, it can:

1. Separate cleanly (harmless PVD)
2. Tear the retina (requires treatment)
3. Lead to retinal detachment if fluid goes through the tear

Warning Signs of Retinal Detachment

• Sudden increase in floaters
• Flashing lights
• Shadow or curtain over part of vision
• Loss of peripheral vision
• This is an emergency—vision can be permanently lost without treatment

How Floaters Are Evaluated

Dilated Eye Exam

• Pupils dilated to see entire retina
• Careful examination for:
  • Retinal tears or holes
  • Signs of retinal detachment
  • Vitreous hemorrhage
  • Inflammation

When Urgent Exam Is Needed

• Sudden new floaters (within 24-48 hours)
• Flashing lights
• Vision changes
• History of eye trauma

Treatment

For Typical Floaters

Usually no treatment needed:

• Most floaters become less noticeable over weeks to months
• Brain learns to ignore them (neuroadaptation)
• They may settle out of the central visual axis

Coping strategies:

• Move your eyes to shift floaters temporarily
• Good lighting can help
• Avoid fixating on them
• Most people adapt over time

When Treatment May Be Considered

Vitrectomy:

• Surgical removal of vitreous
• Reserved for severe, persistent, debilitating floaters
• Carries surgical risks (cataract, retinal detachment)
• Not recommended for typical floaters

Laser Vitreolysis (YAG laser):

• Laser breaks up floaters
• Limited effectiveness
• Not widely recommended
• May not work for all floater types

For Retinal Tears

Laser photocoagulation:

• Creates barrier around tear
• Prevents retinal detachment
• Quick office procedure

Cryotherapy:

• Freezing treatment around tear
• Alternative to laser

For Retinal Detachment

• Surgical emergency
• Various surgical approaches depending on severity
• Early treatment crucial for best outcomes

Natural History

What to Expect

First few weeks:

• Floaters very noticeable
• May be quite bothersome

Over months:

• Floaters often settle lower in eye
• Brain adapts and filters them out
• Most people find them less bothersome

Long-term:

• Many people stop noticing their floaters
• New floaters can develop as aging continues
• Always report sudden changes

Frequently Asked Questions

Are floaters serious?

Most floaters are harmless age-related changes. However, sudden onset of floaters, especially with flashes or vision changes, can indicate a retinal tear or detachment and requires immediate evaluation.

Will my floaters go away?

Floaters rarely disappear completely, but most become much less noticeable over weeks to months as they settle and as your brain learns to ignore them.

Should I see a doctor for floaters?

Yes, especially for new floaters. Any sudden increase in floaters, flashing lights, or vision changes requires prompt examination to rule out retinal problems.

Can screens or reading cause floaters?

No, floaters are not caused by screen use or reading. However, you may notice existing floaters more when looking at bright screens or reading against white backgrounds.

Why do I see floaters more against a blue sky?

Floaters are shadows, and they're most visible against bright, uniform backgrounds like a blue sky or white wall. This doesn't mean floaters are worse—just more visible.

Can exercise or activities make floaters worse?

Normal activities don't affect floaters. However, avoid very strenuous activities or head trauma after a PVD until cleared by your eye doctor.

References