The vitreous changes in 148 eyes with sudden onset of floaters were evaluated biomicroscopically and documented photographically using an El Bayadi-Kajiura aspherical preset lens mounted on a photo slit lamp. Posterior vitreous detachment (PVD) was found in 83% of the eyes. In those eyes, the primary causes of floaters were prepapillary glial tissue on the posterior hyaloid membrane and minimal vitreous hemorrhage. In eyes with no PVD, intravitreous fiber-like opacities corresponding to the patient's symptoms were present in the posterior vitreous cavity near the retina. These opacities were found on the plicated membranes of Cloquet's canal, or were associated with liquefaction of the gel. The symptoms of patients 50 years of age or older were related to the acute onset of PVD in 95% of the cases. The complaint of multiple small floaters was frequently associated with vitreous hemorrhage and retinal breaks.