The following was written by Bill Evans and published in the Coolum and North Shore News, Ask the Professionals page on Friday, 22nd June 2012.
Q: What are floaters?
A: Many people report seeing squiggly lines or cloudy, thread-like substances that seem to float or dart across their field of vision. These are referred to as eye floaters. Inside the eye there is a clear, gel-like substance called the vitreous. Floaters appear if the gel is not clear for any reason, such as debris from the retina or remnants from when the eye was formed. They appear to float in your vision, and because they are inside the eye they move with your eyes when you try to look at them. Floaters are often seen when looking at plain backgrounds such as a white ceiling or the blue sky.
Most floaters are quite benign and harmless though if you notice a sudden change in your floaters, or if you see unusual flashes in your vision, you should have your eyes examined immediately as it may be an indication of something more serious.