Causes of black spots in vision and other types of eye floaters include age-related vision changes, retinal tears, posterior uveitis and bleeding in the eye, according to Mayo Clinic. The floaters appear to drift across the eye and are difficult to look at directly.
Age-related changes in the vitreous, the jelly-like substance inside the eyes, are the most common cause of eye floaters, as stated by Mayo Clinic. As the vitreous liquefies and shrinks over time, microscopic fibers clump together and block light from entering the eye, casting small shadows on the retina. When a sagging vitreous pulls on the retina with excessive force, it can tear the retina and cause floaters. If left untreated, the fluid accumulating behind the retina can cause it to detach, potentially leading to permanent vision loss.
Posterior uveitis, which is the inflammation of the uvea layers located in the back of the eye, also causes floaters. This condition may result from inflammatory diseases and infection. Injury and blood vessel damage can cause bleeding into the vitreous, which often results in floaters. Individuals who experience a sudden increase in floaters should contact an eye specialist immediately, as the condition may require emergency eye care, advises Mayo Clinic.