Small specks or clouds that you see moving about in your field of vision are called floaters. You often see them when looking at a plain background, like a blank wall.

Floaters are actually tiny clumps of gel or cells in the vitreous, the clear jelly-like fluid that fills the back of the eye. While often these objects look like they are in front of your eye, they are actually floating inside.

What you see are the shadows that they cast onto the retina, the nerve layer at the back of your eye that senses light. Floaters can have different shapes: dots, cobwebs, lines, circles, to name a few.