Abstract: An ophthalmic apparatus comprising at least two corrective lenses (5, 5?) that are mounted to a support (113) for supporting the lenses in front of a user's eyes (1, 1?), thereby defining a viewing direction through each lens (5, 5?); at least one of the lenses being a variable focal length lens comprising front (131) and rear (141) superposed lens elements having cooperating optical surfaces that are shaped such that the focal length of the variable focal length lens is variable according to the relative lateral disposition (d) of the front (131) and rear (141) lens elements to provide a power, where d=0 is defined as the relative position of the front (131) and rear (141) lens elements at which the variable focal length lens provides an overall horizontal meridional power ?p corresponding to the intended user's prescription, and where the front lens element (131) has a fixed power ?r and a rear lens element (141) has a fixed power ?r, such that: ?P=?f+?r+?° A wherein O° A is the power provided by the variab

Abstract: A pair of spectacles comprises a pair of variable focal length lenses; an image acquisition system adapted to acquire images of each of a user's eyes; and a controller adapted to analyze the images to monitor the degree of vergence of the user's eyes, and to adjust a focal length of the variable focal length lenses to a value derived directly from the monitored degree of vergence.