Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
"Eye floaters" are deposits or condensation in the vitreous (often referred to as vitreous humor, vitreous fluid, or vitreous gel), the material that fills the posterior part of the eye. People use the term eye floaters to describe seeing floating spots within their vision when they look around. Eye floaters may be present in only one eye or both eyes.
Why do people notice eye floaters?
The structures in the front of the eye (the cornea and lens) focus rays of light onto the retina. Light focused onto the retina allows one to see. The light going to the retina passes through the vitreous humor, which is a jellylike material that occupies the back two-thirds of the eye. At birth and during childhood years, the vitreous gel is usually totally clear and transparent. Later in life, strands, deposits, or liquid pockets very commonly develop within the vitreous gel. Each of these strands casts a small shadow onto the surface of the retina, and these shadows may be perceived by the patient as eye floaters. As the eye moves from side to side or up and down, these strands, deposits, or pockets also shift in position within the eye, making the shadows move and appear to float or undulate.
People describe eye floaters as spots, straight and curved lines, strings, or "O" or "C"-shaped blobs. Some people see a single floater while others may think they see hundreds. The lines may be thick or thin, and they sometimes appear to be branched. To most people, they appear grey and darker in color than the background. The density of different eye floaters will vary within an individual eye. Eye floaters may be more noticeable under certain lighting conditions and be more apparent when looking at a bright sky. Floaters are rarely seen in situations with reduced illumination.
Like fingerprints, no two people have exactly identical patterns of eye floaters. If a person has eye floaters in both eyes, the pattern of the eye floaters in each eye will be different. In any eye that has eye floaters, that pattern of eye floaters may also change over time.
Eye floaters always appear darker than the background and cannot be seen in darkness or with the eyes closed. This is unlike flashes, which often are seen in the dark and with the eyes closed.
Spots in front of the eyes: Also known as "floaters," blurry spots that drift in front of the eyes but do not block vision. The blur is the result of debris from the vitreous casting a shadow on the retina. The spot is the image formed by a deposit of protein drifting about in the vitreous, the clear jelly-like substance that fills the middle of the eye.