A process is described whereby the complex wave equation is transformed into an integro‐differential equation in a single real dependent variable. This makes possible a technique for obtaining wave functions, which is believed to offer definite advantages in some instances where the more standard methods are difficult to handle, e.g., in regions where the complex index is varying rapidly. The index may be entered in a tabulated form, and its exact analytical expression is not required.The technique is then demonstrated by computing the reflection coefficient associated with an extremely critical region, that which one encounters at the ``fourth reflection condition,'' where the refractive index goes through a sharp peak (see reference 3).