| 摘要 |
<p>The present invention relates to very high refractive index glasses (1.78 lt; n lt; 1.83), having the following composition of oxides, expressed in percentages by weight :SiO220- lt; 27B2O35- 11Li2O2- 8Na2O0-5K2O0 -5BaO7 -15CaO0 -11La2O37 -12PbO7 -20TiO27 -14ZrO20 -5Nb2O5 gt; 8-16with: Li2O+ Na2O+ K2O gt; 6BaO +CaO +La2O3 gt; 27TiO2 +Nb2O5 +PbO gt; 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> |
