Floaters are specks or spots that float around in the visual field. The National Eye Institute describes them as "cobwebs" or small, dark shapes that look like squiggly lines that seem to dart away when you look directly at them. The Mayo Clinic notes that most people have a few floaters in their eyes that can be ignored; however, a large number of sudden new floaters may be a symptom of a serious medical emergency.
Common Floaters
Floaters are common especially when looking at something bright, such as the sky. According to Phyllis A. Balch, CNC and James F. Balch, M.D., authors of "Prescription for Nutritional Healing," floaters are bits of cellular debris that are more likely to affect older adults and nearsighted people. You can't actually see the tiny pieces of floating debris but instead experience the shadows cast on the retina as light passes through the eye. The vitreous is a gel-like substance, mostly made of water, that fills the back portion of the eye between the lens and retina. The vitreous gives the eye its shape. Optometrists Marc Grossman and Glen Swartwout, authors of "Natural Eye Care," report that cells or proteins in the vitreous may stick together, appearing as black circles or cones floating in the periphery of the visual field.
Serious Symptoms
Donald S. Fong, M.D., and Robin Demi Ross, M.D., explain that floaters can be caused by bleeding inside the eye, separation of the vitreous from the retina, a posterior vitreous detachment or a combination of both causes. The authors at AllAboutVision.com describe an unusual type of floater called a "doughnut floater" because it is shaped like a doughnut. It is caused by circular pieces of vitreous gel that separate from the optic nerve. The ring may fold in half, creating a J or C shape. People with diabetes are at high risk of floaters that can cause intermittent blurriness. Floaters are also associated with eye injury, inflammation and, on rare occasions, tumors.
Flashing Lights
The presence of floaters with flashing lights may be a symptom of an early tear in the retina. This is a serious medical condition because the tear can cause the retina to detach, causing blindness. According to the University of Michigan Kellogg Eye Center, when the vitreous gel rubs or pulls on the retina, the person might see what appear to be flashing lights. It becomes more common as people age and can continue on and off for several weeks. Doctors Fong and Ross point out that intermittent flashing lights---also called photopsias---usually occur in both the dark and light, because the retina is unable to distinguish the pulling of the vitreous from the retina from light shining on it.
The authors at AllAboutvision.com caution that anyone experiencing a shower of floaters, spots or flashing lights should seek immediate medical care. These sudden symptoms may indicate that the retina is becoming separated from the back of the eye, which contains essential nutrients and oxygen.
References
- University of Michigan Kellogg Eye Center: Floaters and Flashes
- National Eye Institute: Facts About Floaters
- Mayo Clinic: Eye Floaters
- Eye Floaters, Flashes and Spots
- "Foundations of Low Vision"; Anne L. Corn and Alan J. Koenig; 2004
