Abstract: An optical instrument comprising in the observation device thereof a seal (12) between its cylindrical body (3) and its sleeve (76) as well as sealing coupling means (15, 16, 17, 18) between its body and its first support (4), between the sleeve and the second support (8) and between the lenses (6, 10) and their respective supports; and the observation device and the endoscope (2) are further joined together by complementary assembly means formed by a male member (19) and a female member (20) between which is disposed a seal (21).

Abstract: Biopsy forceps for use with a contact endoscope having a body terminating in a distal end comprising a hollow outer tube open at both ends, a hollow inner tube located coaxially within the outer tube, the inner tube being open at its rear end and terminating at its front end in at least one pair of diametrically opposed tongues that extend outwardly beyond the front end of the outer tube and in a direction substantially parallel to the longitudinal axis of the tubes and then bend inwardly at their far end at right angles to the longitudinal axis terminating in a series of teeth to form forceps jaws, the jaws being biased in a direction away from the axis, whereby movement of the tubes in one direction relative to one another causes the tongues of the jaws to slide into the outer tube and the forceps jaws to close and movement in the opposite direction causes the jaws to open, and a control device for axially moving one of the tubes relative to the other to activate the jaws, whereby the endoscope can be inser