Wide field-of-view bifocal eyeglasses

When vision is affected simultaneously by presbyopia and myopia or hyperopia, a solution based on eyeglasses implies a surface with either segmented focal regions (e.g.bifocal lenses) or a progressive addition profile (PALs).However, both options have the drawback of reducing the field-of-view for each power position, which restricts the natural eye-head movements of the wearer.To avoid this serious limitation we propose a new solution which is essentially a bifocal power-adjustable optical design ensuring a wide field-of-view for every viewing distance.The optical system is based on the Alvarez principle.Spherical refraction correction is considered for different eccentric gaze directions covering a field-of-view range up to 45degrees.Eye movements during convergence for near objects are included.We designed three bifocal systems.The first one provides 3 D for far vision (myopic eye) and -1 D for near vision (+2 D Addition).The second one provides a +3 D addition with 3 D for far vision.Finally the last system is an example of reading glasses with +1 D power Addition.