PTSD was significantly associated with ocular surface symptoms both abroad and on return to the United States, whereas air pollution in the form of incinerated waste, was correlated with reversible symptoms.

Purpose: To find out the Centrality of Hirschberg reflex in young emmetropic females and to correlate it with asthenopia. Study Design: Cross-sectional study Place and Duration of Study: Outpatients department of Khalid Eye Hospital, Karachi, from January to December 2019. Methods: Six hundred young emmetropic females 10 to 25 years of age were included. We performed the Hirschberg test and Jackson cross cylinder to assess the astigmatism and observed near point of convergence to find out convergence insufficiency. Results: Out of 600 young emmetropic females only one hundred and ninety had a central Hirschberg corneal reflex along with an astigmatism of 0.25 to 0.50 which was observed in one hundred and sixty five patients. One hundred and twenty five had a receded near point of convergence. Conclusion: Acentrality of Hirschberg can be a cause of asthenopia among young emmetropic females. Key Words:  Asthenopia, Astigmatism, Emmetropia, Hirschberg corneal reflex.