Floaters typically happen because of changes inside the eye. They can be a normal occurrence in many instances, but they can also be an indication of a serious eye problem. Irregularities on the front surface of the eye as well as problems in the visual pathway behind the eye could be causes.
Vitreous Floaters
Most floaters are due to normal changes that occur within the vitreous gel in the posterior chamber of the eye. The posterior chamber is the area inside the eye. The vitreous gel is the transparent matter inside the chamber. Over time, the gel slowly degenerates, and it can begin to change from a clear gel into a material resembling that of a cobweb. This material floats inside the eye and can be more noticeable when looking at an image with a bright background, such as a clear sky. These types of floaters do not cause other vision problems, but they will always persist to some degree.
Sight Threatening Floaters
A retinal detachment is the primary concern when a new floater appears in the vision. The retina is the sight-enabling tissue that lines the back of the eye like wallpaper. If the retina becomes detached and peels away from the back of the eye, then sight is lost where that detachment occurs. The symptoms of a retinal detachment are often a flash of light in the area of the vision where the detachment is occurring, followed by a floater or a visual disturbance in that area. The worst-case scenario is when the vision simply goes black, indicating a full detachment. Retinal detachments require immediate eye surgery to reattach the tissue before permanent damage occurs. Surgical outcomes improve with timely intervention.
Other Causes
Particles within the tear film can result in the appearance of floaters. Allergy sufferers and those who have dry eye syndrome may notice these types of visual floaters. Simple reasons such as debris on a contact lens or an eyelash in the eye could also be a cause. Neurological issues such as a stroke or a migraine headache can result is various types of visual disturbances. More extensive testing may be necessary if a standard eye examination reveals no signs inside that eye that can account for the vision abnormality. Any new symptoms of floaters in the vision should be evaluated by an eye doctor to prevent permanent vision problems.
References
- American Optometric Association: Spots and Floaters
- "The Wills Eye Manual"; Justis P. Ehlers and Chirag P. Shah; 2008
