One day I saw an elderly patient a few days after cataract extraction which was done in another hospital. She presented with a red painful eye. Upon examination I could not see the implanted artificial lens clearly nor the back of the eye because of fulminant inflammatory reaction. The patient had had post operative endophthalmitis. An infection that can cause her to become blind. I immediately had to prepare antibiotic injections to start treating and save her sight. Luckily my trustworthy PDA with Wills Eye Manual & Drug Guide was in my pocket and provided me with accurate dosage on how to prepare the necessary antibiotics - displayed in a clear notated table. During the ensuing week the vision improved and the inflammation decreased. In a busy emergency room, with other patients waiting with a sight saving crisis, every minute counts!