All adult patients with ARDS who are planned for prone ventilation, as decided by the treating physician, will be screened for inclusion in this study. As a part of standard treatment for ARDS, all patients will be receiving lung protective ventilation strategies as per ARDS net protocol with appropriate sedation and paralysis, and also these patients will have relevant invasive and non-invasive vitals monitoring as per ICU protocol. All IOP measurements will be taken by same investigator throughout the study, who will be trained to monitor IOP in ten patients under direct supervision of an experienced ophthalmologist. In studied patients, baseline readings of IOP will be measured by tonometry device before prone positioning in 30-45 degree head end elevation (T1). Next reading of IOP will be measured (T2), 5 minutes after supine position, i.e. during preparation for turning the patient prone. Then, patients will be proned with adequate precautions to avoid ocular compression and rest of the body supported with adequate thoraco-pelvic supports. Duration of prone ventilation will be decided by treating physician. The next IOP will be measured in non-dependent eye at 10 minutes (T3) and 30 minutes (T4) of prone position; and just before making the patient supine (T5). After completion of prone position session, IOP will be measured again in both eyes at 5 minutes after turning the patient in supine without head end elevation (T6), then followed by measurement at 10 minutes (T7), 15 minutes (T8) and at 30 minutes (T9). Last 3 measurements i.e. T7, T8 and T9 will be done in 30-45 degree head end elevation. All IOP values will be recorded as a mean of three readings at each pre-defined time, in both eyes of the patient. Monitored vitals with relevant clinical data will be noted. Patient will be followed till ICU discharge. Detailed ophthalmic examination for anterior segment (which includes IOP measurement); and posterior segment of both eyes will be done in survivors at time of ICU discharge as well as at 1 month and at 3 months, in follow up.