There is no sandardised guidelines internationally in the usage of PPE among Ophthamologist. How exactly it is spreading is still not known completely. The three doctors who died in wuhan , were working in same unit including Dr Li Wenliang. It is believed that, they were treating asymptmatic glaucoma patients. Recent study found Viral RNA in tear film of conjunctivtis patients. Now ophthalmlogist are prefering to use face shield along withN 95 mask, slit lamp breath shield to minmize drople tansmssion and many more.