Ophthalmic no-line progressive addition lenses for spectacles are provided with increased sizes of usable intermediate and near addition zones. A preferred lens of the present invention comprises a distance zone, one or more intermediate addition zones and a near add zone wherein each of the zones has...http://www.google.com.au/patents/US5910832?utm_source=gb-gplus-sharePatent US5910832 - Ophthalmic no-line progressive addition lenses
