Dark spots or squiggles drifting across your vision are called floaters. Seeing a line, spot or thread drifting across your field of vision can be distracting, to say the least. Known as “floaters,” these shadowy movements got their name because they seem to float in the air, moving with your head and eyes.
The chance of developing floaters increases with age, and they are often more noticeable when you are looking at a bright, uniform background, like a white wall or clear blue sky.
What causes these floating shapes to develop? The back of the eye contains a gel-like substance, known as the vitreous, which adheres to the light-sensitive tissue at the back of the eye called the retina. Floaters occur when the collagen fibers in the vitreous clump together and cast shadows on the retina.
Floaters are most common in people over age 50 because this is when the vitreous gel typically begins to degenerate, a process called vitreous syneresis. One of the main causes of floaters is posterior vitreous detachment, which occurs when the shrinking vitreous gel pulls away from the retina entirely. This posterior vitreous detachment is also more common in people who are highly nearsighted, have had eye injury or surgery and have internal eye inflammation.
For most people, floaters aren’t serious and are often seen to disappear with time, as you adapt to them. However, in about 10% of posterior vitreous detachment cases, the vitreous pulls away from the retina with enough force to cause a tear or retinal detachment. Retinal tears and detachments are medical emergencies that can lead to permanent vision loss without quick treatment.
Signs of retinal tears to watch for are 1) a dramatic increase in new floaters, 2) new floaters accompanied by eye pain or redness, 3) flashes of light, especially in your side vision, 4) a dark curtain or shadow creeping across your visual field and 5) a sudden decrease in vision in an eye.
If you notice new floaters, it is a good idea to contact your eye doctor for evaluation. Be advised in about 5% of posterior vitreous detachment cases, retinal tears have no symptoms and are only found during an ophthalmic examination.
The management of floaters due to vitreous degeneration is observation because the floaters can become less symptomatic with time. If floaters become bothersome or affect visual function, vitrectomy surgery to remove the vitreous and replace it with saline can be an option for severe cases.
One of the most critical things to do is pay attention to what you see. If experiencing signs of a retinal tear or detachment, such as a rapid onset of numerous floaters, flashing lights or a dark curtain seen in your vision, it is urgent to be seen by your eye doctor for a retinal examination.
