It usually comes as a shock to most people when they first discern spots or lines drifting across their fields of vision. This phenomenon is most evident when looking up at a clear blue sky or other solid background. These so-called “floaters” are extremely common and not dangerous. Most people experience floaters at some point in their lives, but they tend to disappear over time. Floaters can be explained by age-related changes in the vitreous humor, the jelly-like substance in the eyeball. As this substance shrinks, it tends to clump, which causes shadows to be cast on the retina that the brain perceives as dark spots. If floaters become bothersome and interfere with daily life, laser treatment may be considered.
P.S. The laser treatment used to treat bothersome floaters, laser vitreolysis, utilizes an Nd:YAG laser to vaporize floaters.