Flashes: the commonest example of a flash is when we bang our head and see stars. They can look like fire flies, fireworks or even a disco light. These symptoms are caused when the retina has been stimulated abnormally. While they are unpleasant they are usually not harmful. However if you find you are experiencing a lot of them, especially if you are also experiencing loss of sight, you should be seen by a doctor or an optometrist immediately as it could indicate that you have a torn or detached retina and may need surgery.

Floaters: eyes contain a fluid which is jellylike. Sometimes small particles of things like blood or tissue get into this liquid and move around. They can be different shapes and either a single object or more than one. Like flashes, floaters are mostly harmless and disappear over time but should be checked by a doctor or an optometrist immediately to rule out a torn or detached retina.