Moir+E,acu e+EE topographic measurement

A hand-held instrument (10) and associated method for providing optical measurements of the contour, range and motion of an object, such as a tympanic membrane of an ear, in real time, and to provide for simultaneous visualization of the object. The instrument (10) includes an illumination source (22) that projects an optical beam (24) through a grating (26) onto a gradient of refractive index lens (32) to project light and dark fringes onto the object at stepped phases determined by the grating position. Light reflected from the object is collected and focused onto an eye piece (18) to be observed by the operator. Simultaneously, reflected light from the object is focused onto a camera (46). The camera (46) generates an electrical signal in proportion to the light intensity received by the camera (46) to generate an image of the object. The image is then transmitted to processing systems to compute phase relationships in the reflected grating image to generate a contour map of the object. A drive system (28) is provided to move the grating (26) to different positions at a fraction of the spatial period of the grating during a measurement to provide phase sensitivity, eliminate reflectivity variations and reduce background noise.