Abstract: A lens system comprising a frame that fixes to a head of a user of the lens system. Associated with the system are first and second magnifiers that are movable with respect to each other and with respect to the frame. The first and second magnifiers have respective oculars and objectives. The magnifiers are associated with a distance measuring means for measuring the distance from the user to an object to be viewed by the user. They provide a connected control unit with a signal representative of the distance. Driving means connected to the control unit are provided. The control unit provides the driving means with a control signal in response to the signal received from the distance measuring means. There are first displacement transferring means connected to the driving means for displacing the objectives with respect to the first and the second ocular. The focal length of each magnifier is adapted to the distance measured by the distance measuring means.