Abstract: An elongated image-carrying member that enables microendoscopy to be practiced using normal-sized catheters, includes a drawn, fused, central multi-fiber micro-unit of about 0.5 mm diameter, having about 2,000 glass fibers in coherent array, with a polymeric coating bonded to its pristine as-drawn outer surface. This combination achieves sufficient flexibility and optical qualities to enable effective use to provide vision for inspection of small passages and ducts. Flexible image-carrying members having diameter of 0.5 millimeter or less and catheters of diameter of 3 mm or less incorporating such members and effective working channels are achievable. For vision in remote areas, the micro-unit is employed with a substantially spherical lens with an ocular system for providing a focus range from less than about 2 mm to infinity and having resolution of detail down to the order of about 0.001 inch.