Xa ungena kwivenkile yeglasi kwaye uzama ukuthenga iperi yeglasi, uneentlobo ezininzi zeelensi ongakhetha kuzo ngokuxhomekeke kummiselo wakho. Kodwa abantu abaninzi bayabhideka ngamagama athi umbono omnye, i-bifocal kunye nenkqubela phambili. La magama abhekisa kwindlela iilensi ezikwiiglasi zakho eziyilwe ngayo. Kodwa ukuba awuqinisekanga malunga nokuba loluphi uhlobo lweglasi olufunwa ngugqirha wakho, nantsi inkcazo ekhawulezayo ukukunceda uqalise.
1. Yintoni iiLensi zoMbono omnye?
Ilensi yombono omnye ngokusisiseko yilensi egcina ummiselo omnye. Olu hlobo lwelensi lusetyenziselwa imigqaliselo yabantu ababona kufutshane, ababona kude, abane-astigmatism, okanye abaneempazamo ezidityanisiweyo. Kwiimeko ezininzi, iiglasi zombono omnye zisetyenziswa ngabantu abafuna umlinganiselo ofanayo wamandla ukuze babone kude kwaye bavale. Nangona kunjalo, kukho iiglasi zombono omnye ezimiselwe injongo ethile. Umzekelo, iperi yeglasi yokufunda esetyenziselwa ukufunda kuphela iqulethe ilensi yombono omnye.
Ilensi yombono omnye ilungele uninzi lwabantwana kunye nabantu abadala abancinci kuba ngokuqhelekileyo abafuni ukulungisa ulungiso lombono wabo ngokusekelwe kumgama wabo. Umyalelo wakho weeglasi zombono omnye uhlala ubandakanya icandelo elingqukuva njengenombolo yokuqala kummiselo wakho kwaye unokubandakanya icandelo lesilinda ukulungisa i-astigmatism.
2. Yintoni iiLensi zeBifocal?
Iilensi zeBifocal zineendawo ezimbini ezahlukeneyo zokulungiswa kombono. Imimandla yahlulwe ngomgca ocacileyo ohlala ngokuthe tye kwi-lens. Indawo ephezulu yelensi isetyenziselwa umgama, ngelixa indawo engezantsi isetyenziselwa umbono okufutshane. Inxalenye yelensi enikelwe kumbono okufutshane inokubunjwa ngeendlela ezimbini ezahlukeneyo: icandelo le-D, icandelo elingqukuva (elibonakalayo/elingabonakaliyo), icandelo legophe kunye ne-E-line.
Iilensi zeBifocal zidla ngokusetyenziswa ukuba umntu ungumntu onqabileyo ongakwaziyo ukuziqhelanisa neelensi eziqhubekayo okanye kubantwana abancinci abanamehlo anqamlezayo xa befunda. Isizathu sokuba zingasetyenziswa kancinci kukuba kukho ingxaki eqhelekileyo ebangelwa zii-bifocal lens ezibizwa ngokuba “yi-image jump”, apho imifanekiso ibonakala ngathi iyaxhuma njengoko amehlo akho eshukuma phakathi kwamacandelo amabini elensi.
3. Yintoni iiLensi eziqhubela phambili?
Uyilo lweelensi eziqhubekayo lutsha kwaye luqhubele phambili ngakumbi kunee-bifocals. Ezi lens zibonelela ngethambeka eliqhubela phambili lamandla ukusuka phezulu kwelensi ukuya ezantsi, inika utshintsho olungenamthungo kwiimfuno ezahlukeneyo zombono. Iilensi zeglasi yamehlo eziqhubela phambili zikwabizwa ngokuba yi-no-line bifocal kuba azinamgca ubonakalayo phakathi kwamacandelo, nto leyo ezenza zibe nomtsalane ngakumbi.
Ngaphaya koko, iiglasi zamehlo eziqhubela phambili zikwadala inguqu egudileyo phakathi komgama, ophakathi, kunye neenxalenye ezikufutshane zomyalelo wakho. Inxalenye ephakathi yelensi ilungele imisebenzi yoluhlu oluphakathi njengomsebenzi wekhompyuter. Iiglasi zamehlo eziqhubela phambili zinenketho yoyilo olude okanye olufutshane lwepaseji. Ipaseji yinxalenye yelensi ekunika amandla okubona imigama ephakathi.
Ngelizwi, umbono omnye (SV), i-bifocal, kunye neelensi eziqhubekayo nganye zibonelela ngezisombululo zokulungiswa kombono. Iilensi zombono omnye zichanekile kumgama omnye (kufuphi okanye kude), ngelixa iilensi ze-bifocal kunye nenkqubela phambili zijongana nombono okufutshane kunye nokude kwilensi enye. Ii-Bifocals zinomgca obonakalayo owahlula iinxalenye ezikufutshane kunye nomgama, ngelixa iilensi eziqhubekayo zibonelela ngenguqu engenamthungo, egqibeleleyo phakathi kwemigama ngaphandle komgca obonakalayo. Ukuba ufuna naluphi na ulwazi olungaphezulu, nceda uzive ukhululekile ukuqhagamshelana nathi.