The eye is filled with a gel like substance called vitreous. In babies, the vitreous is firmly attached to the retina, the inner lining of the eye. With age the vitreous thins and may separate from the back of the eye, and this is often accompanied by flashes or floaters. Floaters look like small dark spots or strands that appear in front of your eye. They are caused by cells or tiny bits of gel that cast shadows inside the eye. Floaters are very common and normally harmless. They are more common if you are short-sighted or as you get older. Flashes are due to an interaction between the gel inside the eye moving against the retina. Occasionally flashes or an increase in floaters can be a sign of something serious like a retinal tear, a retinal detachment, bleeding, infection or following a blow to the head. Sometimes flashes or shimmering zigzag lines related to migraines are seen before the headache occurs. These can easily be confused, but the flashes before a migraine are seen with both eyes.
Signs and Symptoms
If you experience the following symptoms, you should get urgent medical attention
- A sudden increase in flashes or floaters
- A new large floater that moves or remains suspended in one place
- A change in floaters or flashing lights after a direct blow to your eye
- A shadow, or curtain, spreading across the vision of one of your eyes
- A sudden loss in vision together with flashes and floaters
Most of the time floaters are harmless. Sometimes they may be annoying, but treatment is not advised. A sudden increase in floaters may be a sign of serious eye disease like retinal detachment and this requires immediate medical attention. An eye care practitioner will use eye drops and a special light to examine your retina and look for damage. Surgery is high risk and only performed when vision is significantly affected.
Although some people are more at risk of retinal detachment than others, it is important to monitor your vision of each eye by simply comparing the two eyes noting the quality of vision and any change.