The present technology relates to an image processing device and a method, and an operating microscope system that enable an operation to be performed more comfortably.An image processing device includes: an image acquisition unit configured to acquire a coaxial illumination image obtained by performing coaxial illumination on an eye being an operation target, and an oblique illumination image obtained by performing oblique illumination on the eye; and an image processing unit configured to generate an operative field image of the eye on the basis of the coaxial illumination image and the oblique illumination image, or detect a specific region on the basis of at least either one of the coaxial illumination image or the oblique illumination image. The present technology may be applied to a microscope system.