The present invention provides novel slow-releasing ophthalmic compositions containing Povidone Iodine (PVP-I) and uses thereof in the treatment of acute infections of at least one eye tissue from bacterial, mycobacterial, viral, fungal, or amoebic causes and for preventing such infections in appropriate clinical settings. Each of the ophthalmic compositions contains povidone iodine, osmotic pressure regulator, suspending agent and EDTA-Na, wherein povidone iodine exists as microsphere particles formed by PVP-I and sodium alginate.