01 Amavili amathathu okusila esandla sokusila anika amanqanaba ahlukeneyo okusila, avumela igcisa ukuba licokise ngokuthe ngcembe imiphetho yelensi. Ivili lokuqala lingasetyenziselwa ukugaya ngokurhabaxa, ukususa izinto ezingaphezulu ngokukhawuleza. Ivili lesibini emva koko ligudisa imiphetho, ngelixa ivili lesithathu nelona licolekileyo liwagudisa ngokugqibeleleyo.
Ukongeza ekusebenziseni kwayo kwimveliso, i-grinder yesandla enamavili amathathu iphinda ifumane isicelo ekulungiseni nasekugcinweni kwee-eyewear ezikhoyo. Ukuba i-lens iyaqhekeka okanye iqhekeke, okanye ukuba isakhelo kufuneka sitshintshwe, igrinder ingasetyenziselwa ukubumba kwakhona imiphetho yelensi ukuze ilingane nesakhelo esitsha.
Ngapha koko, kwindawo yeempahla zamehlo zesiko, igrinder yesandla enamavili amathathu idlala indima ebalulekileyo. Abathengi abaneemilo zobuso ezingaqhelekanga okanye iimfuno ezithile ezibonakalayo banokufuna iilensi ezilungiselelweyo. Igrinder yesandla ivumela umntu ochwepheshile ukuba amise ngokuchanekileyo imiphetho yelensi ukuze ihambelane neekhonto zobuso bomthengi, iqinisekisa ukukhululeka kunye nesimbo.