Eye floaters are the tiny spots or flecks that come into your field of vision. Although they are annoying, they are relatively common and should not be of much concern. It is when there is a shower of floaters, or if they are accompanied by a flash of light, that you should seek immediate medical attention.
Floaters are come from the eye’s gel-like vitreous. Tiny pieces of the gel break and loosen within the eye giving the appearance of tiny spots or cobwebs in the field of vision. The condition is called posterior vitreous detachment (PVD).
As the eye develops, the vitreous gel fills the eye and presses against and attaches to the retina. As time passes, the vitreous becomes more liquid than gel-like in the center of the eye. With the peripheral vitreous gel staying gel-like, it is heavier and collapses into the center of the eye; this causes it to detach from retina.
If there is a sudden arrival of eye floaters (more so than normal) it could mean that the vitreous is pulling away from the retina of the eye. If it is not PVD, then it could mean that the retina is becoming dislodged from the back of the eye lining. This part contains blood, nutrients, and the oxygen that is vital for the eyes to function properly.
If there is retinal tear or detachment, an Ophthalmologist needs to reattach the retina and restore function of the eye before vision is lost permanently. However, floaters on their own are rarely an indication of a retinal detachment.
PVD is far more common cause of light flashes (photopsais) than the detachment of retina (retina detachment is roughly 9%).
When the retina is torn or detached from the eye, a flash or flicker of light is noticed. The size of the tear, or how detached it is, will dictate how long the flashes persist. This will continue to happen until the retina is repaired (if it can be repaired).
Flashes in the eyes can also happen after an injury occurs, such as a blow to the head. If the vitreous gel is shaken inside the eye the condition is referred to as “seeing stars”. This can last anywhere from seconds to 20 minutes.
You can also see flashes that are caused by a spasm of blood vessels in the brain- a pretty severe headache typically follows. These type of flashes (with a headache that follows) is called a migraine. They usually do not cause much concern or any major vision issues, though they are extremely painful and uncomfortable.