Dark shadows drifting in and out of the right eye are generally more difficult to heal on their own. Vitreous clouding is a common cause of dark shadows, which is divided into physiological and pathological. 1. Physiological vitreous clouding: occurs in the elderly, generally does not affect vision, strong light to see the black shadow is clearer, dark light black shadow is not clear, that is, flying mosquito, there is no loss of vision, observation. 2. Pathological vitreous clouding: black shadow floating around to block the line of sight, affecting vision, mostly seen in uveitis, fundus lesions, vitreous hemorrhage, etc., the above cases should be treated in a timely manner, under the guidance of the doctor to choose the laser, surgery and other treatments. The right eye has a black shadow floating around, it is recommended to go to the hospital in a timely manner to clarify the cause, in order to avoid delaying the condition.