Vitreous hemorrhage is a common complication of ocular trauma or retinal vascular disease causing visual harm. On the one hand, hemorrhage not only clouds the refractive medium and prevents light from reaching the retina, but can also have a serious damaging effect on the ocular tissues; on the other hand, the body’s response to hemorrhage allows for the gradual removal of blood. The consequences of vitreous hemorrhage vary greatly from case to case. The symptoms, signs, prognosis and complications of vitreous hemorrhage depend mainly on the primary cause of the hemorrhage and the amount of bleeding, the number of bleeding episodes and other factors. Spontaneous hemorrhage often comes on suddenly and can be very small amounts of bleeding, or in many cases form a thick clot. When a small amount of bleeding occurs, the patient may not be aware of it, or only have “flying mosquitoes”; when more bleeding occurs, the patient feels a dark shadow floating in front of the eyes, or seems to be covered by red glass, and patients with repeated bleeding may feel “smoke” and have a significant loss of vision. On ophthalmologic examination, when the hemorrhage is small and does not interfere with the slit-lamp view, red blood cells can be seen aggregated in a lemon-colored dusty scaffold of vitreous gel. Moderate amounts of fresh hemorrhage may appear as dense black streaks of cloudiness. A large amount of hemorrhage results in no red light reflection from the fundus and vision loss to light perception. Over time, the blood within the vitreous dissipates, the color fades, and the vitreous gradually becomes clear. The absorption of more blood takes 6 months or up to a year or more. In the absence of significant fundus lesions, vision may be fully or mostly restored. In cases of trauma to the posterior segment of the eye combined with massive vitreous hemorrhage, useful vision may be lost in half of the patients.