Floaters, those small dots or cobweb-shaped patches that move or “float” through the field of vision, can be alarming. Though many are harmless, if you develop a new floater, “you need to be seen pretty quickly” by an eye doctor in order to rule out a retinal tear or detachment, said Dr. Rebecca Taylor, a spokeswoman for the American Academy of Ophthalmology.
Floaters are caused by clumping of the vitreous humor, the gel-like fluid that fills the inside of the eye. Normally, the vitreous gel is anchored to the back of the eye. But as you age, it tends to thin out and may shrink and pull away from the inside surface of the eye, causing clumps or strands of connective tissue to become lodged in the jelly, much as “strands of thread fray when a button comes off on your coat,” Dr. Taylor said. The strands or clumps cast shadows on the retina, appearing as specks, dots, clouds or spider webs in your field of vision.
Such changes may occur at younger ages, too, particularly if you are nearsighted or have had a head injury or eye surgery. There is no treatment for floaters, though they usually fade with time.
But it’s still important to see a doctor if new floaters arise because the detaching vitreous gel can pull on the retina, causing it to tear, which can lead to retinal detachment, a serious condition. The pulling or tugging on the retina may be perceived as lightning-like flashes, “like a strobe light off to the side of your vision,” Dr. Taylor said.
See an eye doctor within 24 to 48 hours if you have a new floater, experience a sudden “storm” of floaters, see a gray curtain or shadow move across your field of vision, or have a sudden decrease in vision.