An endoscope comprising: an endoscope housing ; at least one optical fiber disposed within the endoscope housing and configured to provide a path for propagation of a light beam; a distal lens system disposed in the endoscope housing and in the path of the light beam, wherein the lens system comprises: a rigid optical lens ; and a sealed fluid filled lens formed by a flexible membrane member and a face of the rigid optical lens; characterised in that : the flexible membrane member is stretched over the rigid structure of the rigid optical lens; and the endoscope further comprises: a distance sensor coupled near a distal end of the endoscope and configured to determine a distance between the distal end and an object disposed in front of the distal end, and compare the distance with a focal length of the sealed fluid filled lens; an actuator coupled to the sealed fluid filled lens and configured to change an optical power of the sealed fluid filled lens; and a controller coupled to the actuator and configured to operationally instruct the actuator to change the optical power of the sealed fluid filled lens based on the comparison. an endoscope housing ; at least one optical fiber disposed within the endoscope housing and configured to provide a path for propagation of a light beam; a distal lens system disposed in the endoscope housing and in the path of the light beam, wherein the lens system comprises: a rigid optical lens ; and a sealed fluid filled lens formed by a flexible membrane member and a face of the rigid optical lens; a rigid optical lens ; and a sealed fluid filled lens formed by a flexible membrane member and a face of the rigid optical lens; characterised in that : the flexible membrane member is stretched over the rigid structure of the rigid optical lens; and the endoscope further comprises: a distance sensor coupled near a distal end of the endoscope and configured to determine a distance between the distal end and an object disposed in front of the distal end, and compare the distance with a focal length of the sealed fluid filled lens; an actuator coupled to the sealed fluid filled lens and configured to change an optical power of the sealed fluid filled lens; and a controller coupled to the actuator and configured to operationally instruct the actuator to change the optical power of the sealed fluid filled lens based on the comparison. the flexible membrane member is stretched over the rigid structure of the rigid optical lens; and the endoscope further comprises: a distance sensor coupled near a distal end of the endoscope and configured to determine a distance between the distal end and an object disposed in front of the distal end, and compare the distance with a focal length of the sealed fluid filled lens; an actuator coupled to the sealed fluid filled lens and configured to change an optical power of the sealed fluid filled lens; and a controller coupled to the actuator and configured to operationally instruct the actuator to change the optical power of the sealed fluid filled lens based on the comparison. a distance sensor coupled near a distal end of the endoscope and configured to determine a distance between the distal end and an object disposed in front of the distal end, and compare the distance with a focal length of the sealed fluid filled lens; an actuator coupled to the sealed fluid filled lens and configured to change an optical power of the sealed fluid filled lens; and a controller coupled to the actuator and configured to operationally instruct the actuator to change the optical power of the sealed fluid filled lens based on the comparison. <EOS>