Njengoba igama liphakamisa, isibuko se-bifocal sinokukhanya okubili. Ngokuvamile, isetshenziselwa ukubona ibanga, njengokushayela nokuhamba ngezinyawo; Okulandelayo ukubona ukukhanya okuseduze, ukubona okuseduze, njengokufunda, ukudlala umakhalekhukhwini nokunye. Lapho i-bifocal lens isanda kuphuma, yayibhekwa njengezindaba ezinhle ngempela kubantu abane-myopia + presbyopia, ehlanganisa nenkinga yokukhetha nokugqoka njalo.
I-Bifocal lens piece isuse inkathazo ye-myopia kanye ne-presbycusis yokukhetha nokuguga njalo, bheka kude naseduze ungabona ngokucacile, intengo futhi ishibhile.