| 摘要 |
<p>The present invention relates to very high refractive index glasses (1.78 < n < 1.83), having the following composition of oxides, expressed in percentages by weight :SiO220- < 27B2O35-11Li2O2-8Na2O0-5K2O0-5BaO7-15CaO0-11La2O37-12PbO7-20TiO27-14ZrO20-5Nb2O5 > 8-16with: Li2O+Na2O+K2O > 6BaO+CaO+La2O3 > 27TiO2+Nb2O5+PbO > 29,to their use for the production of segments for multifocal corrective lenses and to multifocal corrective lenses incorporating at least one such segment in their structure.</p> |
