Ubukhulu beLens kwiiglasi buphenjelelwa zizinto ezininzi, phakathi kwazo amandla e-lens eyona nto iphambili.Ubukhulu beLens yeMyopia ePhakamileyo bujiyile kunobo beMyopia ephantsi.Nangona kunjalo, xa kuziwa kubukhulu obupheleleyo, ububanzi beLens bubalulekile, kwaye ukukhetha isakhelo esincinci kunokunciphisa kakhulu ubukhulu beLens.Ubume beLens bukwabalulekile, njengeMyopia kwindawo engqindilili yeperipheral yeLens econcave, iHyperopia kumbindi oshinyeneyo weConvex Lens kunye neperipheral ebhityileyo.
Isalathisi se-refractive (Juni 20) ye-lens yimpawu ebalulekileyo kunye nento evumela ukuba isigulane silawule ubukhulu beLens.Isalathiso se-refractive ngumlinganiselo wesantya apho ukukhanya kudlula kwindawo ethile (efana neglasi, amanzi, iplastiki, umoya) ukuya kwinqanaba layo kwi-vacuum.Ukuphakama kwesalathiso se-refractive, isezantsi izinga lokudluliselwa kokukhanya phakathi, kunye nokucaca ngakumbi ukukhanyela ukukhanya.Ngaloo ndlela, i-lens ene-high refractive index i-refracts ukukhanya ngokufanelekileyo kwaye ngoko incinci kune-lens ene-low refractive index.
Iiglasi bezisenziwa ngeglasi kangangeenkulungwane, yaye ezinye izigulana zisagxininisa kwiilensi zeglasi kuba zivakalelwa kukuba zibanika owona mgangatho ubalaseleyo wokubonwayo.Iilensi zeglasi zanamhlanje zenziwe kwiCrown Glass, imathiriyeli ene-chromatic aberration ephantsi kunye nokumelana nokukrwela.I-Crown Glass inesalathiso esiphezulu se-refractive, nangaphezulu kuneso seelensi ezininzi zeplastiki.Nangona kunjalo, ngenxa yobuninzi bayo obuphezulu, iglasi yesithsaba inzima kuneelensi zeplastiki ezinesalathiso esifanayo se-refractive, nangona iilensi zeplastiki zihlala ziba ngqindilili.Izigulane zidla ngokukhetha iilensi ezikhaphukhaphu, yiyo loo nto zikhetha iilensi zeplastiki ngaphezu kweglasi yesithsaba.
Iplastiki esemgangathweni yeeglasi zefreyimu yi-Columbia Resin-39 (CR-39) .Le yimathiriyeli yelensi elungileyo, iyamelana nokukrweleka, kwaye inobunzima besiqingatha kuphela njengelensi yeglasi efanayo.Nangona kunjalo, isalathiso sayo esisezantsi sithetha ukuba iLens ingqindilili xa yenziwe kwiiglasi eziphezulu zediopter.
Iintlobo ngeentlobo zezixhobo zeplastiki zelensi ziye zaphuhliswa, ezikhokelela kwisalathisi esiphezulu se-refractive kodwa sincinci, iilensi ezilula.Okufana ne-polycarbonate (1.586), i-polyurethane (1.595) kunye neglasi yezixhobo ezizodwa (1.70) .Ezi lens azikho ngqindilili kunezinye izigulane ze-myopic, ngelixa zibonelela ngenani eliphezulu lokuphakama.Nangona kunjalo, ezinye zezi zixhobo zineempazamo ezinkulu kunezixhobo ezisezantsi ze-refractive index kwaye azinyamezelwa lula.Uninzi lwezi zixhobo zithambile, zixhathisa ukophuka kuneglasi okanye iplastiki ye-CR-39, kodwa ithanda ukukrwela.
Ixesha lokuposa: Jul-28-2021