Ya kamata a yi la'akari da nau'i-nau'i na ruwan tabarau masu dacewa da kanka a hade tare da digirinmu, nisa na dalibi, siffar firam, kasafin kuɗi, amfani da yanayin da sauran dalilai.
Fihirisar refractive kamar girman takalmi ne. Ba tare da la'akari da alamar ba, waɗannan su ne sigogi na gama gari, waɗanda za a iya fahimtar su a matsayin kauri na ruwan tabarau. Mafi girman ma'anar refractive, mafi ƙarancin ruwan tabarau. Iri guda 500 myopia, ruwan tabarau 1.61 shine bakin ciki 1.56.
Ko da yake mafi girma da refractive index ne, da bakin ciki shi ne. Gabaɗaya magana, mafi girman ma'anar refractive shine, ƙananan lambar Abbe shine. Zaɓi matakin da ya dace da kanka
Mabambantan firikwensin refractive suna da lambobin Abbe daban-daban. Waɗannan lambobin Abbe ne masu dacewa da maƙasudai daban-daban:
1.50
Abun lamba 58
Babban lambar Abbe mai girma yana kusa da kwarewar gani na ido tsirara. Lens mai siffar zobe zai kasance mai kauri sosai idan matakin ya yi girma. Ya dace kawai don ƙananan digiri na myopia a cikin digiri 250. Tsarin tushe yana da girma, kuma bai dace da manyan gilashin firam ba.
1.56
Abbe lamba 35-41
Lambar Abbe tana da matsakaici, 1.56 ita ce mafi ƙasƙanci mafi ƙasƙanci na yawancin nau'ikan ruwan tabarau, wanda yake da arha kuma ya dace da myopia a cikin digiri 300; Ba a ba da shawarar ba idan zafin jiki ya wuce digiri 350. Lens zai yi kauri lokacin da digiri ya fi girma.
1.60
Abbe mai lamba 33-40
1.60 da 1.61 halaye ne daban-daban na rubuce-rubuce tare da maƙasudin refractive iri ɗaya. Babu bambanci. Dangane da iri daban-daban da jerin, adadin Abbe ya bambanta daga 33-40. Misali, kariyar radiation na wata mai haske 1.60 shine 33 dB, kuma jerin PMC na wata mai haske shine 40 dB.
1.67
Abbe lamba 32
Low Abbe lambar, babban tarwatsawa da babban tasirin hoto. A cikin kewayon 550-800 digiri myopia, 1.61 yana da kauri sosai, kasafin kuɗi yana iyakance, kuma bai wuce 1.71 ba, don haka 1.67 shine zaɓi na sulhu.
1.71
Abbe lamba 37
Gabaɗaya magana, mafi girman ma'anar refractive na ruwan tabarau, ƙananan lambar Abbe kuma mafi girma watsawa. Koyaya, tare da ci gaban fasahar kayan ruwan tabarau, ana karya wannan doka. Misali, 1.71 ya fi 1.67 sirara, kuma lambar Abbe ta fi girma.
1.74
Abbe lamba 33
Mafi kyawun fihirisar mai da hankali da lambar Abbe na ruwan tabarau na guduro ba su da ƙasa, kuma farashin yana da girma. Koyaya, ga babban myopia, babu wani zaɓi. Bayan haka, kauri koyaushe shine ƙwarewa mafi mahimmanci. Ana iya la'akari da sama da digiri 800, kuma fiye da digiri 1000 ana iya la'akari da su ba tare da tunanin wani abu ba. Daidai daidai 1.74.
Lokacin aikawa: Maris-09-2023