Floaters or “flying flies” (myodesopsia)

Floaters or “flying flies” (myodesopsia) are small spots (in the form of threads, dots, spider webs) that many people see moving in their visual field, especially when they look at a background with intense contrasts (blank pages, clear sky, etc…)

They are the result of the presence of opacities that form in the vitreous humor, the gelatinous body that fills the eyeball, and with the passage of light cast their shadow on the retina. In most cases, they are a natural consequence of the aging of this vitreous body, which is losing water and decreasing in volume. As a result, the vitreous proteins, that have lost water, condense losing transparency. Although these spots appear to be in front of the eye, they actually float inside the eye.

Generally, they are of little importance and are related to the aging process, but sometimes this vitreous gel can be separated from the retina, causing tears and haemorrhages, because of that, its sudden onset can be a warning signal and visualization of the fundus is necessary.

Image of floaters (myodesopsia)


They usually occur due to the aging of the gelatinous material of the vitreous, which when losing its content in water can begin to thicken or shrink, forming agglutinations within the eye that cause its separation from the retina.

This posterior vitreous detachment is more common in myopic patients who have undergone some ocular intervention or who suffer from ocular inflammations. Diabetes is also mentioned as the cause of its appearance.

Can they be prevented?

Floaters cannot be prevented. What can be and should be detected are the possible complications associated with them. It is important to see an ophthalmologist when:

  • Their sudden appearance is observed.
  • They are accompanied by flashes (photopsia).
  • They are accompanied by loss of vision in some region of the visual field.