Cov tsom iav tsom iav kho qhov yuam kev los ntawm kev khoov (refractive) lub teeb thaum nws hla lub lens. Lub peev xwm khoov lub teeb (lub zog ntawm lub lens) uas xav tau los muab kev pom kev zoo tau qhia rau ntawm daim ntawv yuav tshuaj tsom iav uas koj tus kws kho qhov muag muab.
Qhov yuam kev ntawm kev pom kev tsis meej thiab lub zog ntawm lub lens uas yuav tsum tau kho lawv raug ntsuas ua cov chav hu ua dioptres (D). Yog tias koj qhov muag pom kev luv me ntsis, koj daim ntawv yuav tshuaj yuav hais tias -2.00 D. Yog tias koj qhov muag tsis pom kev ntau, nws yuav hais tias -8.00 D.
Yog koj pom kev deb, koj xav tau cov iav lo ntsiab muag "plus" (+), uas tuab dua hauv nruab nrab thiab nyias dua ntawm ntug.
Cov iav iav lossis cov iav yas ib txwm rau cov neeg uas pom kev luv lossis pom kev ntev tuaj yeem tuab thiab hnyav heev.
Zoo hmoo, cov chaw tsim khoom tau tsim ntau yam khoom siv yas tshiab "high-index" uas khoov lub teeb kom zoo dua.
Qhov no txhais tau tias siv tsawg dua cov khoom siv rau hauv cov iav siab-index los kho qhov yuam kev refractive tib yam, uas ua rau cov iav yas siab-index nyias dua thiab sib dua li cov iav iav lossis yas ib txwm muaj.
Cov txiaj ntsig ntawm cov iav lo ntsiab muag siab
Nyias dua
Vim lawv muaj peev xwm khoov lub teeb tau zoo dua, cov iav tsom iav siab rau cov neeg pom kev luv luv muaj cov npoo nyias dua li cov iav tsom iav uas muaj lub zog zoo ib yam li cov uas ua los ntawm cov yas ib txwm muaj.
Lub teeb
Cov npoo nyias dua yuav tsum siv cov khoom siv lens tsawg dua, uas ua rau qhov hnyav tag nrho ntawm cov lens txo qis. Cov lens ua los ntawm cov yas uas muaj cov khoom siv siab dua yog sib dua li cov lens tib yam uas ua los ntawm cov yas ib txwm muaj, yog li lawv xis hnav dua.
Thiab feem ntau cov iav tsom iav siab kuj muaj tus qauv tsim aspheric, uas ua rau lawv nyias dua, zoo nkauj dua thiab txo qhov zoo li lub lens ib txwm ua rau hauv cov ntawv sau tshuaj ntev.
Cov kev xaiv lens siab index
Cov iav yas uas muaj cov qib siab tam sim no muaj ntau yam refractive indexes, feem ntau yog txij li 1.60 txog 1.74. Cov iav uas muaj refractive index ntawm 1.60 & 1.67 yuav nyias dua li 20 feem pua ntau dua li cov iav yas ib txwm muaj, thiab 1.71 lossis siab dua feem ntau yuav nyias dua li 50 feem pua.
Tsis tas li ntawd, feem ntau hais lus, qhov siab dua qhov ntsuas, qhov siab dua ntawm cov iav tsom iav.
Koj daim ntawv yuav tshuaj ntsuam kuj txiav txim siab seb koj xav tau hom khoom siv uas muaj cov ntsuas siab npaum li cas rau koj lub lens. Cov khoom siv uas muaj cov ntsuas siab tshaj plaws feem ntau yog siv rau cov ntawv yuav tshuaj uas muaj zog tshaj plaws.
Feem ntau ntawm cov qauv tsim thiab nta ntawm cov iav niaj hnub no — suav nrog Dual Aspheric, Progressive, Bluecut Pro, Prescription tinted, thiab cov iav photochromic Spin-coating tshiab — muaj nyob rau hauv cov ntaub ntawv siab. Txais tos rau nyem rau hauv peb nplooj ntawv ntawmhttps://www.universeoptical.com/armor-revolution-product/kom paub ntxiv.