La ikati ukuphazamiseka kwe- umbono okwenzeka lapho ilensi, le lens encane eyisiyingi etholakala ngemuva komfundi, ilahlekelwa yiyo obala.

Lapho i-crystalline kuba namafu, imisebe yokukhanya ifinyelela i-retina kancane, okuchaza ukuthi kungani ukufiphala kombono. Igama elithi cataract lakhethwa ukuthi lichaze lo muzwa wokubuka ngempophoma (kusuka esiLatin ikati, okusho impophoma). Ilensi lidlala indima efanayo nelensi yenhloso yekhamera enezithombe: ukugxila esithombeni ngokuya ngebanga elisuka entweni ebonwayo. Ilensi ikwenza lokhu ngokukhubazeka ukushintsha indlela egobile ngayo.

Imvamisa, i-cataract yakha kancane, ifayili le- ukuguga. Ngokuhamba kwesikhathi, ukwakheka kwelensi kuyashintsha. Asazi kahle ukuthi kungani, kepha okucatshangwayo okuyinhloko ukuthi amaprotheni elensi aguqulwa ngama-radicals amahhala, izinto ezikhiqizwa ngokwemvelo ngumzimba futhi ezinomthelela ekugugeni. Ama-radicals amahhala ahlukaniswa kancane ngama-antioxidants, ikakhulukazi atholakala kwizithelo nemifino esetshenzisiwe.

I-cataract imele i-3^e imbangela ubumpumputhe eCanada. Izimbangela eziyinhloko zobumpumputhe - ukonakala kwe-macular, i-glaucoma kanye ne-cataract - imvamisa kwenzeka ngokuguga.

Ubani othintekayo?

Kusukela iminyaka 65, iningi labantu lisheshe lifike ikati. Ukugqama kwelensi akubangeli ukungakhululeki okubonakalayo uma kwenziwa ezingxenyeni ezisemaphethelweni zelensi.

Ngemuva kweminyaka yobudala ye- iminyaka 75, izingxenye ezimbili kwezintathu zabantu baseMelika zinolwelwesi oluthuthuke ngokwanele ukuphazamisa umbono wazo. I- ukulahleka kombono ivame ukuba yimbi ngokukhula. I-cataract ithinta abesilisa nabesifazane.

izinhlobo

Kunezinhlobo eziningana zamehlo, okulandelayo okuyizona eziphambili.

• I-cataract kaSenile. Iningi lamakhathakhatha atholakala kubantu asebekhulile. Inqubo ejwayelekile yokuguga ingaholela ekuqiniseni nasekusibekeni kwamalensi. I-cataract ehlobene nobudala ivame ukuthinta iso elilodwa ukwedlula elinye.
• I-cataract yesibili. Ukugula okuthile (ikakhulukazi isifo sikashukela, uma kungalawulwa kahle), ukuthatha imishanguzo ethile (ngokwesibonelo, i-cortisone ethathwe ngomlomo), noma ukuvezwa yimisebe ephezulu yemisebe kungaba imbangela yokhakhayi. Ngaphezu kwalokho, ukuhlinzwa kwamehlo noma ukuba nezinkinga ezithile zamehlo (njenge-myopia ephezulu, i-glaucoma noma i-retinal detachment) kukwenza ube sengozini yokuphathwa yiso.
• I-cataract ehlukumezayo. Kwenzeka njengomphumela wokulimala kweso okulimaza ilensi: ukushaywa, ukusika, ukuchayeka ekushiseni okukhulu, ukushiswa kwamakhemikhali, njll.
• I-cataract ezinganeni. I-cataract ingaqala kusukela ekuzalweni, kepha kuyaqabukela. Kungahambisana nesifo sokuzalwa (ngokwesibonelo, i-trisomy 21) noma kubangelwe yisifo esithathelwanayo esivela kumama esidluliselwe embungwini ngesikhathi sokukhulelwa, njenge-rubella, i-toxoplasmosis, i-herpes yesitho sangasese noma ugcunsula.

Evolution

Nini'ukubona okuhle kwehle kuze kube seqophelweni lokuvimbela kakhulu imisebenzi yansuku zonke, lokhu kungakhombisa ukuthi kungenzeka ukuthi unamehlo. Imvamisa, lokhu kulahleka kombono kwenzeka kancane, ngaphezu kweminyaka eminingana. Kodwa-ke, kwesinye isikhathi kwenzeka ngokushesha okukhulu (ezinyangeni ezimbalwa).

Lapho i-cataract isithuthuke kakhulu, i- umfundi ayisabonakali emnyama, kepha iba mpunga noma a amhlophe ubisi. Esigabeni esithuthukile, umbono ungakhawulelwa ekubukeni kokukhanya.

Ukubonisana nini?

La ikati kuvame ukutholwa ngesikhathi se- ukuhlolwa kwamehlo ngudokotela wamehlo. Noma yiluphi ushintsho kwikhwalithi yombono kufanele ludlulise ukubona i-ophthalmologist.