Floaters & Flashes
Small specks or clouds moving in your field of vision as you look at a blank wall or a clear blue sky are known as floaters. These are normal occurrences for most people, becoming noticeable when they become more numerous. Floaters are part of the aging process and can appear as squiggly lines, tiny bugs, and so on. The floaters are actually shadows created from pieces of vitreous (the clear, gel-like substance inside the eye), which break off from the retina.
Flashes occur when the vitreous separates from the retina, and can appear as a lightening streak or as twinkling "stars."