<prompt> Which is the commonest cause of ocular morbidity globally?CataractRefractive errorOcular injuryVitamin A deficiency  <response>: Uncorrected refractive error remains a major cause of vision loss throughout the world. When included in the global statistics, uncorrected refractive error accounts for over 18 of profound vision loss, with a much larger percentage of moderate and severe vision loss. Ref: Pirbhai A, Kent S, Hodge W.G. 2011. Chapter 20. Causes and Prevention of Vision Loss. In Riordan-Eva P, Cunningham E.T., Jr Eds, Vaughan Asburys General Ophthalmology, 18e. 