A New York County jury has awarded 5 million to a 73 year-old man who lost vision in an eye as the result of an infection caused by unsterile conditions while undergoing retinal surgery nearly 9 years ago. The jury made the award Tuesday to Michael Weres following an eight-day trial before State Supreme Court Justice Arthur E., in Brooklyn against the East 91st hospital, of which Dr. Raymond Castroviejo, the surgeon, was the proprietor. The malpractice left the plaintiff totally blind since he had lost vision in his other eye because of an unrelated almond. Castroviejo had previously settled for $600,000. The plaintiff was represented by Rosenberg & Horowitz, the hospital, by David Skolnick of Gorden and Silber.