Although eye floaters are very common and usually are not cause for alarm, there are some situations in which they may be a medical emergency.
Eye floaters are typically described as tiny spots, specks, or “cobwebs” that appear randomly in vision. They are often noticed when looking at a bright, clear sky or a white computer screen.
Floaters appear in our vision when tiny pieces of the eye’s vitreous break loose. The vitreous is the transparent, colourless gelatinous mass that fills the space between the lens of the eye and the retina lining the back of the eye. As we get older, the vitreous begins to dissolve causing some of its gel particles to float around in the now watery center of the vitreous. What we see as a floater is actually not the vitreous particle; it’s the particle’s shadow, which is cast on the retina as light passes through the eye.
If at any time you see a shower of floaters and/or spots, often times accompanied by light flashes, you should seek medical attention immediately. These symptoms may indicate that the vitreous is actually pulling away from the retina or the retina is becoming dislodged from the inner back of the eye – a condition called a retinal tear or detached retina.
If indeed there is a retinal tear or detachment, an eye surgeon must immediately reattach the retina and restore function before vision is lost permanently.
Ophthalmologist Thomas Henderson M.D. explains, “As we age, in half the people over the age 50, the vitreous jelly of our eye will separate from its normal attachment point at the optic nerve in the back of the eye. This will cause a single, or a few, mobile dark floaters just lateral to the line of sight, often accompanied by a transient superior lateral arc of light from above to the horizontal. In 2% of the people with a vitreous separation, the retina will tear, often crossing a blood vessel and causing a few blobs and blotches that diffuse into clouds that break up into hundreds of tiny dots, typical of blood in the back of the eye. In 1 in 1,000 people with a vitreous separation, the retina will detach, allowing fluid to go underneath the retina through a retinal tear, separating the retina from its normal blood supply and causing a dark area in the peripheral vision. Both of these symptoms represent an emergency and should be reported to the ophthalmologist for prompt examination to obtain the best results from treatment and prevent possible permanent impairment of sight in the affected eye.”