Ukunciphisa umfundi kusiza umbono wezakhi zangaphakathi zeso kufaka phakathi i-lens, i-nertic optics, imithwalo yegazi nokubuyisela ngokuningiliziwe. Ukuxilonga kuyisici esibalulekile sokuhlolwa kwezilanga olunzulu , njengoba ngezinye izikhathi kuholela ekutholeni nasekuhloleni izifo ezithile zeso.
Umfundi wesiso ufana nokuvula ikhamera okungaba mkhulu noma kumancane kuncike ekukhanyeni okudingekayo ukungena iso.
Umfundi angaba ngaphansi kwe-miosis, okuyiyona isisindo sokulingana komfundi ukuba abe mncane noma singathola i-mydriasis, okuyi-dilation yomfundi noma ukukhulisa ubukhulu bomfundi. Ubukhulu bomfundi bulawulwa yizo zombili uhlelo lokuzwelana kanye nesistimu ye-neasympathetic yezinzwa.
Usayizi womfundi uguquka kuye ngokuthi inani lokukhanya elingena elweni. Usayizi wesonto ungashintsha njengempendulo kwisenzo socansi. Usayizi wesonto uphinde uguquke ezikhathini zokucindezeleka. Kucatshangwa ngokuthi "ukulwa noma indiza" ukucabanga ukuthi kubangelwa ukukhuliswa kobukhulu bomfundi ukuze kuvunyelwe ukukhanya okukhulu emehlweni ukuze umzimba ungasabela ngokushesha ngokushesha ezitheni ezinobungozi.
Kunezinhlobo ezimbili zamaconsi eso ophthalmic. Olunye uhlobo luvuselela ukuchotshozwa kwemisipha e-iris ekwandisa umfundi kanye nolunye uhlobo luvuselela imisipha eyenza i-pupillary constriction futhi iphinde ivuselele imisipha evumela iso lethu ukuba ligxilise ilensi ngaphakathi kweso lethu.
Amanye alawa amaconsi ejoka anikezwa ndawonye ukwenza umfundi abe mkhulu.
Ukunciphisa iso njengengxenye yokuhlolwa kweso kuhilela ukuhlinzeka ngamaconsi ama-eye emilenzeni ngezinye izikhathi aqondisa izikhathi ezimbili noma kathathu ngqo emehlweni. Kuncike kulokho udokotela azama ukufezekisa nokuthi umfundi kumele abe mkhulu kangakanani, izinhlobo ezahlukene zamaconsi eziso zinganikwa.
Izibonelo zamaconsi eziso ezenza umfundi ahlaziye:
- phenylephrine
- tropicamide
- i-hydroxyamphetamine
- i-cyclopentolate
- i-atropine
Iningi, kodwa hhayi yonke, ukudonsa amaconsi kubangela umphumela ohlangothini we- cycloplegia . I-Cycloplegia yikukhubazeka okwesikhashana komzimba we-ciliary ovumela iso ukuba ligxile ezintweni eziseduze. Amaconsi amaningi okukhuphuka angabangela umphumela we-cycloplegic noma kuphi kusuka emahoreni ambalwa kuya ezinsukwini ezimbalwa. Ukuhlukunyezwa komfundi kanye ne-cycloplegia yizinqubo ezimbili ezihlukene kodwa zixhunywe ngoba imithi eminingi eyenza i-cycloplegia, iphinde ikhulise umfundi.
Odokotela bangase bafune ukwenza isiguli sibe ne-cycloplegia. Isibonelo, indlela yokugxila kwengane encane kakhulu inamandla, okwenza kube nzima kakhulu ukukala umbono wabo noma iphutha lokubheka ukuze ubone ukuthi ukulungiswa kombono kuyadingeka yini. Uma isidakamizwa sinikezwa ukwenza i-cycloplegia ebalulekile, uhlelo lokugxila kwengane lukhubazekile okwesikhashana. Ngale ndlela, udokotela angakwazi ukulinganisa kahle uhlelo lokubukwa kwengane ngokuphelele. Empeleni, "idatha eluhlaza" ingalinganiswa kuphela futhi ingane ayikwazi ukuthonya isilinganiselwa nhlobo.
Ngesinye isikhathi lapho udokotela angase afune ukudala isiguli ukuba sandise i-cycloplegia yilapho isifo seso, isimo noma ukuhlukunyezwa okubangela ubuhlungu obukhulu nokuzwela okukhanya.
Ngesimo esibizwa nge- uveitis , i-cycloplegic isohla amaconsi akhonza ukunciphisa ubuhlungu nokuzwela.
Noma kunjalo, ngezinye izikhathi umphumela wecycleplegic side awufunwa. Isibonelo, lapho isiguli sihlanjululwa njengengxenye yokuhlolwa kwehlohlo olunzulu, ngokuvamile ihlupheka ngezinga le-cycloplegic. Amahora ambalwa, umbono wabo oseduze ungase uphazamise. Ngokuvamile, udokotela unesithakazelo ekubukeni izakhiwo zangaphakathi zeso ukucacisa impilo ye-eye futhi ayinasithakazelo ekwenzeni i-cycloplegia. Ngenxa yalesi sici esingasadingeki, le ngxenye yokuhlolwa kwamehlo ibhekwa njengengxenye "embi kunazo zonke" ekuhlolweni kwamehlo futhi ingase igweme ukuza ngenxa yayo.
Ngaphezu kwalokho, lapho kuqhutshwa ihlazi lokudonsa, umfundi ukhulu kakhulu. Ngenxa yokuthi umfundi akakwazi ukubeka ngokujwayelekile ngenxa yamaconsi, abantu bazwela kakhulu. Lokhu ukuzwela ukukhanya kwesikhashana kungenye isizathu esenza abantu bangase bayeke ukuhlolwa ukuhlolwa kweso.
Ngenxa yokuthi ukuhlushwa kwabafundi kuvame ukudala ukuvota noma ukuvalelwa kombono ukuze kuvezwe futhi kuzwele ukukhanya, izibuko ezilahlwayo zivame ukuhlinzeka emva kokuhlolwa ukunciphisa ukungakhululeki okubangelwa ukukhanya kwelanga. I-dilation ngokuvamile ihlala amahora amathathu kuya kweziyisithupha, kodwa akuyona into engavamile ukuba iphele amahora angu-24 kwezinye iziguli, kuye ngokuthi amaconsi asehlotsheni asetshenzisiwe.
Futhi Uyaziwa ngokuthi: "ukunciphisa amehlo"