Devices providing adjustable optical power have previously been proposed for use as corrective lenses in prescription eyeglasses. There is disclosed a lens having optical power adjustable by relative lateral translation of two lens elements, the lens comprising: a first lens element sealed to a cover to define a cavity therebetween; a second lens element disposed within the cavity and coupled to an elongate drive element extending laterally from the second lens element, the second lens element being arranged to be driven laterally relative to the first lens element by lateral translation of the elongate drive element to thereby adjust the optical power of the lens, the lens comprising a lateral projection into which the cavity and drive element extend, the lateral projection having there mounted an adjuster for driving lateral translation of the elongate drive element. The lens reduces or prevents the ingress of dirt, moisture, sweat and grease between surfaces of the lens elements. There is also disclosed an eyeglasses frame, such as may be particularly suited to said adjustable power lens.