For most people, these shadowy figures—known as eye floaters—are a harmless visual quirk. However, for those dealing with anxiety, floaters can become a significant source of distress.

Ever noticed those irritating transparent worm-shaped objects floating around in your line of sight? As soon as you focus on them, they disappear. As soon as you look away, they come right back.

The authors propose that floaters are usually diffraction patterns cast on the retina by red blood cells They are the spots that most people occasionally see before their eyes.