Tree-shaped black shadows before the eyes open are usually caused by retinopathy, physiologic vitreous clouding, and fundus hemorrhage. 1. Retinopathy: If the patient suddenly has a black shadow in front of his eyes after a trauma or strenuous exercise, which has a significant impact on the patient’s vision, it may be caused by retinal detachment or retinal tear. 2. Physiological vitreous clouding: if the patient’s eyes appear small mosquitoes or small flies like small black shadows, mostly caused by vitreous clouding, the impact on vision is not obvious, generally can be gradually adapted to, do not need special treatment. 3. Retinal hemorrhage: if the patient suddenly appeared in front of a large black shadow, may be the fundus hemorrhage diffusion to the vitreous cavity caused by. It is recommended that patients with dark shadows in the eyes should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.