Abaningi bethu banenhlanhla ngokwanele ukuba bangadingi ama-eyeglass ngenxa yobuningi bethu bokuqala. Khona-ke ngokuzumayo, lapho sineminyaka engama-40, siqala ukuzwa izinkinga zokugxila lapho sizama ukufunda. Kubonakala sengathi ukuphrinta okuncane kunzima kakhulu futhi kulukhuni ukufunda. Abantu abaningi bathi ukuguga nje. Ekuqaleni, kubonakala sengathi umbono wethu oseduze ukugxila ubambezelekile noma uhambe kancane.
Amehlo ethu angase akhathele futhi singathola ikhanda uma sizama ukufunda isikhathi eside. Abanye abantu kufanele babambe ifoni noma enye idivaysi yedijithali kancane kancane ukuze bakwazi ukuyibona. Njengoba iminyaka iqhubeka ngemva kweminyaka engamashumi amane, kungase kubonakale sengathi konke ngaphakathi kwezingalo-ubude buba bukhulu kakhulu. Lokhu kuthiwa i-presbyopia.
I-Presbyopia Yivamile
I-Presbyopia ithinta okungcono kakhulu kithi. Le syndrome ibizwa ngokuthi "isifo sengqondo esingaphezu kuka-40." Yebo, ixhunyaniswe neminyaka yobudala, kodwa umuntu akufanele abe nomuzwa wokuthi ulahlekelwa amehlo abo. I-Presbyopia inqubo evamile. Emakhulu eminyaka edlule, isilinganiso sempilo sasingaphezu kuka-40. Ngenxa yalokho, i-presbyopia ayizange ibe yinkinga. Njengoba isilinganiso sethu sokuphila senyukile senyukela eminyakeni ecishe ibe ngu-80 ubudala, i-presbyopia isibe yinkinga yangempela eyithinta impilo yethu yansuku zonke.
Izinguquko zomzimba
I- cornea , isakhiwo esicacile, esifana ne-dome ehlangothini langaphambili leso lethu, sinesibopho esingama-75% endleleni ukukhanya kugxile kwi-retina yethu ukuze sibone izithombe ngokucacile.
Nokho, ngaphakathi kweso lethu yi-lens crystalline, etholakala ngemuva kwe-iris, ingxenye enemibala yeso lethu. I- lens crystalline ibukeka njenge-lens yekhamera futhi inesibopho se-25% samandla okugxila kweso. Ivumela ukuba senze izinguquko ezincane, ezisheshayo, ezinamandla ekugxileni kwethu ekugxileni njengoba sibheka kude ukusuka kuzo zonke izindawo eziphakathi.
Isebenza ngendlela efana ne-auto-focus system kumakhamera. Emkhatsini we-lens kuyinto imisipha okuthiwa i-ciliary muscle. Lezi zinkontileka ze-muscle futhi ziphinde zenzeke, zivumele i-lens ukuba ilulaze ibe yincipha noma ihlehlise ukuze ibe namandla phakathi. Lezi zingqinamba zivumela i-lens ukuba ishintshe ukuma futhi ibangele ukuguqulwa kwamandla okuphelele kweso elingagcina izinto kugxile njengoba sibheka izinto ezahlukene.
Njengoba sikhula, izinguquko ziphinde zenzeke ngaphakathi kwe-lens okubangela ukuthi ilahlekelwe ukuguquguquka kwayo. Siphinde silahlekelwe ukulawulwa okuncane phezu kwemisipha yomzimba we-ciliary futhi sinciphisa kancane. Ososayensi nodokotela banomuzwa wokuthi kuhlanganiswe lezizinto ezimbili ezihlanganisa futhi zisenze sihlakulele i-presbyopia.
Isidingo samalazi
I-Presbyopia iqhubeka kancane futhi ibangela ushintsho olubalulekile embonweni wethu oseduze nophakathi phakathi kweminyaka engu-40 kuya ku-60. Lokhu kusho ukuthi singabona izinguquko ezizungeze iminyaka engu-40 neminyaka embalwa, umbono wethu oseduze ungase ubonakale ubi kakhulu. Ngenxa yalezi zinguquko, udokotela wakho wezilanga angase anikeze amadivaysi angama-optical ahlukahlukene ukuze akuvumele ukuba ube nombono omuhle, osebenzayo eduze. Lawa madivaysi angase abe ngabafundi abanobuchwepheshe obuningi, izibuko zokufundwa komuthi, ama- bifocals , ama-trifocals noma akukho-line, ama-lens okuqhubekayo.
Ngezinye izikhathi amalingo okuxhumana nawo angase abekwe.
Abantu abaningi bayayeka ukuvakashela odokotela babo ngoba bezwa sengathi "bayangena" futhi "kuzongenza amehlo ami ahlale encike noma abe mabi kakhulu uma ngigqoka izibuko." Nakuba udokotela angashukumisa ukuthuthukiswa kweso lomuntu ngokumisela amadivayisi angaphansi kweminyaka engu-7, kubantu abadala, lokhu ngeke kwenzeke. Kubantu abadala, ukugqoka amalensi okulungisa ngeke kubonakale buthakathaka noma kubenze babe bancike kubo. Ungase ujwayele ukususa umbono ukuze uqaphele ukuthi umehluko omkhulu kangakanani embonweni oqondisiwe futhi ongalungile, kodwa amalensi okulungisa azosiza nje ukugxila ikhamera yakho.
Isidingo sokwandisa amandla wezibuko zokufunda yonke iminyaka embalwa izokwenzeka noma ngaphandle kwama-lens okulungisa ngoba isimo sibuhlungu ngokwemvelo kusuka eminyakeni engu-40-60.
> Umthombo:
> Benjamin, uWilliam J no-Irvin M. Borish. I-Borish's Clinical Refraction, uhlelo lwesibili, i-Butterworth-Heinemann-Elsevier, ngo-2006.