Shadows in your vision can be a difficult thing to describe to your ophthalmologist. Different types of shadows can be associated with very different vision issues. For example, serious but common conditions, such as age-related macular degeneration, which can lead to partial or complete loss of central vision, may include a gradual full-vision darkening, sort of like the effect of peering through a sheer dark veil.
Retinal detachment, which most often results from vitreous fluid pulling away from and tearing the retina – and more rarely from injury, can bring about similar visual shadowing, but also may cause dark spots or light flashes to appear in the field of vision. But if the shadow is more like a tiny dark dot, squiggly line, or web, you may be experiencing a more common, less harmful affliction known as eye floaters.
Eye floaters are caused by the binding together of minuscule fibers in the vitreous humor, a gel-like substance in the eye, which becomes more fluid as we age. These microscopic strands are suspended in the liquid and appear as shadows on the retina, moving as the eye moves. For most people, the effects are negligible, and many are able to just ignore the minimal annoyance of the nearly transparent shadows flitting across their field of vision, especially since these floaters are more noticeable when looking at a bright surface like a blank screen or white wall.
If you experience these tiny shadows in your vision, don’t panic. One or two floaters are common for most people. However, if you suddenly see a greater number of them or they are accompanied by flashes of light in your vision, see your eye doctor right away, as this may indicate a more serious condition, like detachment of the retina, described above.