Overview

Eye floaters are spots in your vision. They may look to you like black or gray specks, strings or cobwebs that drift about when you move your eyes and appear to dart away when you try to look at them directly.

Most eye floaters are caused by age-related changes that occur as the jelly-like substance (vitreous) inside your eyes becomes more liquid. Microscopic fibers within the vitreous tend to clump and can cast tiny shadows on your retina, which appear to you as floaters.

If you notice a sudden increase in eye floaters, contact an eye specialist immediately — especially if you also see light flashes or lose your peripheral vision. These can be symptoms of an emergency that requires prompt attention.

Symptoms

Symptoms of eye floaters may include:

  • Spots in your vision that appear as dark specks or knobby, transparent strings of floating material
  • Spots that move when you move your eyes, so when you try to look at them, they move quickly out of your visual field
  • Spots that are most noticeable when you look at a plain bright background, such as a blue sky or a white wall
  • Spots that eventually settle down and drift out of the line of vision

When to see a doctor

Contact an eye specialist promptly if you notice:

  • Many more eye floaters than usual
  • A sudden onset of new floaters
  • Flashes of light
  • Darkness on the sides of your vision (peripheral vision loss)

These painless symptoms could be caused by a retinal tear, with or without a retinal detachment — a sight-threatening condition that requires immediate attention.

Causes

Eye floaters may be caused by:

  • Age-related eye changes. Eye floaters most commonly occur as a result of age-related changes in the vitreous, the jelly-like substance that fills your eyeballs and helps maintain their round shape. Over time, the vitreous partially liquefies — a process that causes it to pull away from the eyeball's interior surface. As the vitreous shrinks and sags, it clumps and gets stringy. Bits of this debris block some of the light passing through the eye, casting tiny shadows on your retina.
  • Inflammation in the back of the eye. Posterior uveitis is inflammation in the layers of the uvea in the back of the eye. Posterior uveitis, which can cause eye floaters, may be caused by infection or inflammatory diseases, among other causes.
  • Bleeding in the eye. Bleeding into the vitreous can have many causes, including injury and blood vessel problems.
  • Torn retina. Retinal tears can occur when a sagging vitreous tugs on the retina with enough force to tear it. Without treatment, retinal tear may lead to retinal detachment — an accumulation of fluid behind the retina that causes it to separate from the back of your eye. Untreated retinal detachment can cause permanent vision loss.

Risk factors

Factors that can increase your risk of floaters include:

  • Age over 50
  • Nearsightedness
  • Eye trauma
  • Complications from cataract surgery
  • Diabetic retinopathy
  • Eye inflammation
Jan. 17, 2015
References
  1. Facts about floaters. National Eye Institute. http://www.nei.nih.gov/health/floaters/floaters.asp. Accessed Nov. 6, 2014.
  2. Sendrowski DP, et al. Current treatment for vitreous floaters. Optometry. 2010;81:157.
  3. Tintinalli JE, et al. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York, N.Y.: The McGraw Hill Companies; 2011. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=40. Accessed Nov. 7, 2014.
  4. Riordan-Eva P, et al. Vaughan & Asbury's General Ophthalmology. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=720. Accessed Nov. 7, 2014.