SIMULTANEOUS VISION OPTICAL LENS FOR CORRECTING FAR-SIGHTEDNESS

摘要

The proximity P of a simultaneous vision optical lens for correcting presbyopia is defined as the reciprocal of the distance D at which a light ray parallel to and at a distance h from its axis crosses the axis after passing through the lens. The curve representing the proximity P of the lens lies between a lower envelope curve Pinf and an upper envelope curve Psup satisfying the following equations: Pinf=f(h)=( SIGMA A'i hi)+PVL Psup=f(h)=( SIGMA A''i hi)+PVL in which PVL is the proximity for distant vision and A'i, A''i are numeric coefficients depending on the proximity addition added for near vision to the proximity for far vision. The lens may be implemented as a contact lens, an intra-ocular implant or an intra-corneal lens.