Xa ungena kwivenkile yeeglasi uze uzame ukuthenga iiglasi, uneentlobo ezahlukeneyo zeelensi onokukhetha kuzo kuxhomekeke kumyalelo wakho. Kodwa abantu abaninzi bayadideka ngamagama athi single vision, bifocal kunye neprogressive. La magama abhekisa kwindlela eziyilwe ngayo iilensi kwiiglasi zakho. Kodwa ukuba awuqinisekanga ngohlobo lweeglasi ozifunayo kumyalelo wakho, nantsi ingcaciso emfutshane yokukunceda uqalise.
1. Zithini iiLensi zoMbono omnye?
Ilensi yombono omnye ngokuyintloko yilensi ephethe umyalelo omnye. Olu hlobo lwelensi lusetyenziselwa amayeza abantu ababona kufutshane, ababona kude, abane-astigmatism, okanye abaneempazamo zokungahoyi. Kwiimeko ezininzi, iiglasi zombono omnye zisetyenziswa ngabantu abafuna amandla afanayo ukuze babone kude nakufutshane. Nangona kunjalo, kukho iiglasi zombono omnye ezimiselwe injongo ethile. Umzekelo, iiglasi zokufunda ezisetyenziselwa ukufunda kuphela ziqulathe ilensi yombono omnye.
Ilensi yokubona enye ifanelekile kubantwana abaninzi nakubantu abadala abancinci kuba abadli ngokufuna ukulungisa indlela ababona ngayo ngokusekelwe kumgama abakuwo. Ilensi yakho yokubona enye ihlala iquka into engqukuva njengenombolo yokuqala kwilensi yakho kwaye ingaquka nenxalenye yesilinda yokulungisa i-astigmatism.
2. Zithini iilensi zeBifocal?
Iilensi zeBifocal zineendawo ezimbini ezahlukeneyo zokulungisa umbono. Ezi ndawo zahlulwe ngumgca ocacileyo ohleli ngokuthe tye phezu kwelensi. Inxalenye ephezulu yelensi isetyenziselwa umgama, ngelixa inxalenye esezantsi isetyenziselwa ukubona kufutshane. Inxalenye yelensi ezinikele ekuboneni kufutshane inokubunjwa ngeendlela ezimbini ezahlukeneyo: icandelo le-D, icandelo elijikelezileyo (elibonakalayo/elingabonakaliyo), icandelo lejika kunye ne-E-line.
Iilensi zeBifocal zihlala zisetyenziswa ukuba umntu akakwazi ukuziqhelanisa neelensi eziqhubekekayo okanye kubantwana abancinci amehlo abo aqhekekayo xa befunda. Isizathu sokuba zingasasetyenziswa kakhulu kukuba kukho ingxaki eqhelekileyo ebangelwa ziilensi zeBifocal ezibizwa ngokuba yi "image jump", apho imifanekiso ibonakala ngathi iyatsiba njengoko amehlo akho ehamba phakathi kwamacandelo amabini elensi.
3. Zithini iiLensi eziqhubekekayo?
Uyilo lweelensi eziqhubekekayo lulutsha kwaye luphucukile kunee-bifocals. Ezi lensi zibonelela ngamandla aqhubekekayo ukusuka phezulu kwelensi ukuya ezantsi, zibonelela ngotshintsho olungenamthungo kwiimfuno ezahlukeneyo zokubona. Iilensi zeglasi eziqhubekekayo zikwabizwa ngokuba yi-no-line bifocal kuba azinamgca ubonakalayo phakathi kwamacandelo, nto leyo eyenza zibe nomtsalane ngakumbi.
Ngaphezu koko, iiglasi zamehlo eziqhubekekayo zikwadala utshintsho oluhamba kakuhle phakathi komgama, phakathi, kunye nenxalenye ekufutshane yeresiphi yakho. Inxalenye ephakathi yelensi ifanelekile kwimisebenzi ephakathi efana nomsebenzi wekhompyutha. Iiglasi zamehlo eziqhubekekayo zinokukhetha uyilo lwendlela ende okanye emfutshane. I-corridor ngokuyintloko yinxalenye yelensi ekunika amandla okubona umgama ophakathi.
Ngamafutshane, iilensi zombono omnye (SV), ezimbini, kunye neelensi eziqhubekekayo nganye nganye zibonelela ngezisombululo ezahlukeneyo zokulungisa umbono. Iilensi zombono omnye zilungele umgama omnye (okufutshane okanye okude), ngelixa iilensi ezimbini kunye neziqhubekekayo zijongana nombono okufutshane nokude kwilensi enye. Iilensi ezimbini zinomgca obonakalayo owahlula iindawo ezikufutshane nezikude, ngelixa iilensi eziqhubekekayo zibonelela ngotshintsho olungenamthungo, olunemigangatho phakathi komgama ongenamgca obonakalayo. Ukuba ufuna naluphi na ulwazi oluthe kratya, nceda unxibelelane nathi.