Injector devices and methods for using them to deliver medicament into a patient's body, e.g., sub-retinally within an eye, are provided. The injector includes an injector cannula having a soft injector tip. A retractable tip protector tube is slidably disposed on the flow cannula between an extended position in which the tip protector tube covers the entire injector tip, and a retracted position in which the tip protector tube is retracted proximally thereby exposing at least part of the injector tip. Accordingly, the tip protector tube protects the injector tip from being damaged while advancing the injector tip to a target injection site.