An endoscope is described in which the diameter of the image relay assembly is less than that of the objective lens assembly. An endoscope sheath is also described for sheathing the endoscope and housing or directing optical fibers for use in illuminating the endoscope view of view. An endoscope-sheath system is further described comprising the combination of the endoscope and the endoscope sheath in eccentric alignment to reduce fluid flow impedance between the two.