Disclosed herein are devices and methods for generating stereoscopic views of the eye (or any desired anatomic structure) using a dual-camera portable computing device. The locations of the two cameras are fixed, and the camera lenses may have different focal lengths. For example, the focal length of the second camera lens may be longer than the focal length of the first camera lens. One variation of a detachable imaging system comprises an objective lens and a relay lens that are disposed over the two cameras. The relay lens may be disposed over the first and second cameras, and have a focal length that is greater than the focal length of the first camera lens and less than or equal to the focal length of the second camera lens.