Flashes and Floaters

What are Floaters?
Our eye is filled with a gel-like substance called the vitreous. When we are born the vitreous is very formed and fills the inside of our eye. Over time as we age, the vitreous begins to shrink and liquefy. This results in tiny clumps and strands of vitreous that cast shadows on the retina that we sense as floaters. They can look like little circles, lines or cobwebs that move around with eye movement. They are often more noticeable when looking at a white background or the sky. The development of these floaters is a normal part of aging and happens to everyone. They usually gradually worsen as we get older.

Are All Floaters Harmless?
A sudden onset of many new or large floaters can be concerning. Other more serious causes for floaters include bleeding in the eye (vitreous hemorrhage) or ocular inflammation (uveitis). In these cases the floaters may be perceived as darker and the vision may get blurrier. Common causes for a vitreous hemorrhage include a retinal tear, a retinal detachment or diabetic damage. Inflammation in the eye can occur from a wide range of causes and can be recurrent. If you ever have a sudden onset of new floaters you should call our office immediately.

What is a Posterior Vitreous Detachment (PVD)?
Eventually, as we get older and the vitreous gel shrinks and becomes more liquefied, the gel separates from the back of the eye. This event is called a posterior vitreous detachment (or PVD). A PVD is completely normal and eventually happens to everyone; however, it is also the time when most eyes have the highest risk of developing a retinal tear. This is because the vitreous gel becomes more mobile and the gel can pull and open up a tear in an area of the retina where it is more adherent to it. If you have an onset of new large floaters with or without flashing lights, you should call our office immediately.

A PVD usually occurs after the age of 60. However, it can occur earlier if you have a history of myopia (near sightedness), ocular inflammation (uveitis), cataract or other intraocular surgery, or trauma to the eye.

Why Do Some People Perceive Flashes with Floaters?
Flashes can be a sign of traction (or pulling) on the retina. People often describe them as sudden arcs of light that last for only a second. Flashes often occur with a formation of a PVD because the vitreous becomes more mobile and the vitreous can pull on the retina in areas where it is more adherent. This can sometimes cause a retinal tear or detachment.

If I Have Floaters, When Should I Be Concerned and Call Your Office?
You should call our office immediately if you experience any of the following:

  • You have a sudden onset of many new, large or dark floaters
  • You have a sudden onset of flashes that persist or increase in frequency
  • You have a decrease in vision
  • You see a shadow or part of your vision missing