1.523 Gilashin Bifocal Photochromic Photogreey Lens na gani na gani

Idan daidaitawar idon mutum ya raunana saboda tsufa, yana buƙatar gyara hangen nesa daban don hangen nesa da kusa. A wannan lokacin, ya / ta sau da yawa yana buƙatar saka gilashin biyu daban-daban, wanda ba shi da kyau. Don haka, ya zama dole a niƙa mabambantan iko guda biyu a kan ruwan tabarau ɗaya don zama ruwan tabarau a wurare biyu. Ana kiran irin wannan ruwan tabarau na bifocal ko gilashin bifocal.

Nau'in Fusion:shi ne don haɗa kayan ruwan tabarau tare da babban maƙasudin refractive a cikin yanki mai ma'ana akan babban farantin a babban zafin jiki, kuma ma'anar refractive na babban farantin yana da ƙasa. Sa'an nan kuma gudu a cikin farfajiyar ƙananan yanki don yin lanƙwasa na ƙananan yanki daidai da na babban yanki. Babu ma'anar shata. Karatuttukan ƙarin A ya dogara ne da ikon jujjuyawar F1 na farfajiyar gaba na filin hangen nesa, curvature FC na ainihin madaidaicin baka da rabon fusion. Matsakaicin fusion shine alaƙar aiki tsakanin ma'anar refractive na kayan ruwan tabarau na lokaci biyu, inda n ke wakiltar ma'auni mai jujjuyawa na babban gilashin (yawanci gilashin rawanin) kuma ns yana wakiltar ma'anar refractive na ƙaramin takarda (gilashin flint) tare da babban darajar, to, fusion rabo k=(n-1)/(nn), don haka A=(F1-FC)/k. Ana iya gani daga wannan dabarar da ke sama cewa a ka'idar, canza yanayin gaban gaban babban farantin, madaidaicin arc da ginshiƙan faranti na iya canza ƙarin digiri na kusa, amma a zahiri, ana samun gabaɗaya ta hanyar canzawa. ma'anar refractive sub-platet. Tebur 8-2 yana nuna ma'aunin gilashin ƙaramin takarda da aka saba amfani da shi a cikin duniya don kera nau'ikan madubin haɗin fuska daban-daban.