The appearance of black floating objects in the eye are usually shadows cast on the retina, caused by clumping in the liquid within the eye, known as the vitreous humor. However, eye floaters could signify serious conditions.
Clumping in the vitreous humor is the most common cause of floaters, and it generally occurs with aging. Inflammation in the back of the eye, posterior uveitis, can be caused by an infection or an inflammatory disease, and it results in floaters. Bleeding or vitreous hemorrhaging is more serious, and it can be the result of an injury; one of the symptoms is the appearance of floaters. Retinal tears can also cause floaters to appear, and the tears should be treated immediately to prevent loss of vision.