Acute respiratory distress syndrome (ARDS) commonly complicates acute illness in intensive care units (ICU). This syndrome is associated with high morbidity and mortality. In management of ARDS patients, lung protective ventilation and prone ventilation are key strategies which have shown survival benefits in recent years and now become standard part of care in these patient. Prone positioning used for surgeries in operation room has been reported with ocular complications, of which vision loss is one of the devastating complications. There is scarcity of literature on effect of prone positioning on intra-ocular pressure (IOP) in critically ill patients. The purpose of our study is to evaluate the effect of prone position on IOP in critically ill patients and follow up for other ocular complication among survivors.