Inkcazo: uEmmetropia ligama elisetyenziselwa ukuchaza imbono yomntu xa kungekho mpazamo yokuphikisa okanye ukugxilwa kwe-focus. U-Emmetropia ubhekisela kwiso elingenalo iziphene ezibonakalayo. Imifanekiso eyenziwe kwi-eye emmetropic ijoliswe ngokupheleleyo, icace kwaye ichanekile.
Amehlo anemmetropia ayifuni ukulungiswa kombono . Xa umntu emmetropia kumabini omabili, umntu uchazwa njengombono ontle.
Xa iliso liyi-emmetropic, imisebe ekhanyayo ezayo kwiso ukusuka kude iya kugxininisa ngokugqibeleleyo kwi-retina.
Ukuba iliso libude obungavamile okanye i-cornea yenziwe ngendlela engavumelekanga, amathuba awuyi kuba yi-emmetropic. Ukuba iliso lomntu lide kunomyinge, ukukhanya kungajoliswa phambi kwe-retina endaweni ngqo kuyo. Oku kunokubangela ukuba kube lula. Ukuba iliso lomntu lifutshane kakhulu, imifanekiso ijoliswe emva kwe-retina. Oku kubangele ukujonga.
Umqathango jikelele we-emmetropia okanye indlela iso liqhubekela phambili ekuthandeleni inzululwazi kunye noogqirha beziliso. Ulwazi malunga nendlela umntwana okhulayo okhula ngayo ukuya kwi-emmetropization uya kuba nethemba ngokubonisa iindlela ezintsha zokulungisa iziphene zokuzikhumbuza, ezifana nokujonga okufutshane kunye nokujonga izinto okanye ukufumana iindlela zokukhusela ukwanda kwiphutha yokubamba. Inkqubo yokumisa ingacaciswanga kakuhle kodwa kucatshangelwa ukuba ifumaneke ngombono obonakalayo, umsebenzi wengqondo, i-genetics kunye nezinye iindlela apho i-defocus inokuchaphazela ukukhula kweso.
Ukuba awuyi-emmetropic, ngoko unesiphene sokumelana. Imizekelo yesiphambeko sokukhupha ilandelayo.
- Ukufuphi kwamehlo : Ukujonga ngokukhawuleza, okanye i-myopia, yimeko apho izinto ezikufuphi zibonakala ngokucacileyo, kodwa ezikude ziphazamiseke. Ukujongana noBuchule kunokufumana ilifa kwaye kudla ngokufunyanwa ngethuba lobuncinci. Nangona kunjalo, unako ukuhlakulela ukusondela kwintsapho ekudala. Abantu abahlakulela i-myopia ekukhuleni kwabantu abadala abasayi kuba nemali ephezulu yokujonga.
- Ukubhekela phambili : Ukujonga phambili, okanye i-hyperopia (ekwabizwa ngokuba yi-hypermetropia), ngokuqhelekileyo yenza ukuba izinto ezikude zibonwe ngokucacileyo, kodwa izinto ezikufutshane zibonakala ziphazamisekile. Ukujonga phambili kudla rhoqo kwiintsapho. Xa umntu enamazinga aphakamileyo aphezulu, umbono wakhe umgama ungabonakalisa ukongeza kwimbono yabo esondeleyo. Abantu abaninzi baphosisa ukungaboni kakuhle kwe-presbyopia, iiposa yokuphikisa edlalwa ngaphezu kweminyaka engama-40 ubudala.
- I-Astigmatism : I-Astigmatism idlalwa xa i- cornea ine-curve. I-cornea yinto ephihliweyo kwinqanaba elilodwa, kubangela umbono obonakalayo. I-Astigmatism ingabangela umbono ophazamisayo kuyo yonke imimandla, kwaye ihlala ihamba kunye nokujonga okanye ukujonga. Uninzi lwabantu lunenani elincinci le-astigmatism. Amanani amakhulu kakhulu njenge-astigmatism abangela ukuphazamiseka ngaphezu kwembono ephosakeleyo. Iimali eziphakamileyo kakhulu ze-astigmatism ngezinye iinkhathi zinzima ukufikelela kwimiboniselo ye-20/20.
- I-Presbyopia : I-Presbyopia yindlela yokuguga yesiqhelo kwiso. Yilahleko ye-lensity of lens eyenzeka ngokuguga, okwenza kube nzima ukugxila kwiindawo ezikufutshane. Iingcali zenzululwazi nazo zikholelwa ukuba ngaphezu kokulahlekelwa kwe-lens, i-muscle eyenza i-lens iguquke ingqalelo, ebizwa ngokuba ngumzimba we-ciliary, iphinda iqalise ukusebenza. I-Presbyopia idla ngokuphawulekayo emva kweminyaka yobudala engama-40-45 ubudala kodwa abantu abaphakathi kwama-35-40 bangabonisa iimpawu zokuqala ngokuxhomekeka kwimeko yabo yokubukeka, umsebenzi kunye nendlela yokuphila