Ubuningi bokubukeka kuyindlela yokubona kahle. Esinye sezici ezibaluleke kakhulu ekuhlolweni kwamehlo, ukuhlolwa kwezinto ezibonakalayo kuzosiza udokotela wakho wezinyathelo ukuthi anqume ukuthi awudingi yini ukulungiswa kombono noma cha.
Ukuhlola okubonakalayo kwezinto ezibonakalayo akulona indawo yokuhlolisisa amehlo okuphelele . Kodwa-ke, ingenye yezilinganiso ezibaluleke kakhulu umuntu angayenza lapho ehlola uhlelo lomuntu olubukwayo.
Ubuningi obubonakalayo bungabuye buhlolwe kude futhi kusondele.
Ubude bokubukeka kokubukeka
Ubude obubonakalayo obubonakalayo buyingxenye yesilinganiso sakho sokulahleka kombono. Ilinganiswa ngokuhlola into encane kunazo zonke ongayibona, ngokuvamile eshadini itholakala ngamamitha angu-20 kude. Lesi silinganiso sibhalwa njengengxenyana, nge 20/20 kuthathwa njengombono ovamile. Ubude obubonakalayo obubonakalayo buvame ukuvivinywa ngokuhlukanisa iso ngalinye bese lilinganisa amehlo womabili ndawonye. Ezimweni eziningi, ishadi lamehlo lisetshenziswe ngobukhulu obuhlukahlukene bezinhlamvu ezitholela kancane futhi ezincane.
Eduzane ne-Visual Acuity
Eduzane ne-acuity ebonakalayo yisilinganiso sokuthi ungabona kanjani izinto eziseduze kahle. Ngokujwayelekile kulinganiswa cishe ngamasentimitha angu-16, kuyindlela enhle yokukala ikhono lakho lokubhekana nemisebenzi efana nokufunda noma yokuthunga. Ezimweni eziningi, eduze kwezinto ezibukwayo zilinganiswa ngamehlo avulekile. Uzocelwa ukuba ubambe ikhadi eliphansi elisendaweni engamasentimitha angu-16 futhi ufunde umzila omncane kunokwenzeka.
I-Visual Acuity ephakathi
Ubuhle obubonakalayo obubonakalayo buyingxenye yokuthi ubona kahle kanjani ibanga lobude bendawo noma kwenye indawo phakathi kwebanga nakude. Nakuba kungenjalo isilinganiso esivamile ekuhlolweni kwamehlo, sekubaluleke nakakhulu ukuba odokotela bezilingo bahlole ubuciko obubonakalayo obuphakathi ngoba lokhu kubanga lapho amakhompiyutha amaningi asethwe khona.
Kuyini Ukuthi Ukube Nesimo Sengama-20/20 Sisho?
Kunezindlela eziningi zokukala ubunzima bokubukwa. Isilinganiso esisodwa sobuciko obubonakalayo esetshenziswa kakhulu yi-Snellen acuity acuity, ebizwa ngokuthi i-ophthalmologist yaseDutch, uHerman Snellen futhi yasungulwa ngo-1862. Inqwaba ye-Snellen ebonakalayo ibalwa njengengxenyana futhi imelwe njengendlela ibanga elihlolwa ngalo ibanga elingakanani lapho i-optotype encane ekhonjisiwe ibonisa i-angle yemizuzu emihlanu ye-arc futhi imininingwane yalowo mbono ubeka iminithi engama-1 we-arc. I-optotype iyincwadi eqinisekisiwe, ukuma, isithombe noma inombolo esetshenziselwa ukukhombisa isihloko esibukeka ngayo ubuningi bokubukeka. Ukusebenzisa uhlelo lwe-metric, ifomula ibanga lokubuka ngamamitha ngaphezu kwesayizi yamagama kuma-M-amayunithi. Ngakho, 6/6 kufana no 20/20.
Ubuciko obubonakalayo buka-20/20 busho ukuthi umuntu angabona imininingwane encane kusuka kumamitha angu-20 kuyafana nomuntu onamehlo ajwayelekile angabona kusuka kumamitha angu-20. Uma umuntu enobuciko obubonakalayo obuyi-20/40, kuthiwa ubona imininingwane esuka kumamitha angu-20 kuyafana nomuntu onamehlo ajwayelekile angayibona kusuka kumamitha angu-40 kude. Kubonakala sengathi umuntu ojwayelekile noma obonakalayo obonakalayo obonakalayo u-20/20. Kodwa-ke, kunabantu abaningi abangabona i-20/15 nabambalwa abangathola ngisho nokubonakala okubonakalayo kwe-20/10.
Kungenzeka ukuba nombono ophakeme kunama-20/20: ubuhle obukhulu besiso lomuntu ngaphandle kwezinsiza ezibukwayo (njengama-binoculars) ngokuvamile kucatshangwa ukuthi kuphakathi kuka-20/10.
Umthombo:
Association American Optometric (AOA). Ukubukeka okubonakalayo: Kuyini 20/20 Umbono? I-AOA, 2006-10.