Isizwe ngasinye seMhlaba sinombala obalaseleyo weenwele, isikhumba kunye namehlo. Umzekelo: phakathi kwabemi baseLatin America, i-80-85% yabemi, i-Ukraine kunye neRashiya - i-50% kunye ne-30% - ingafunyanwa amehlo omdaka. Ubumnyama balukhuni lwabazali, lukhulu amathuba okubonakala kwamehlo omdaka nomnyama omnyama.
Ubungakanani bombala wamehlo kumntwana
Ngokuqhelekileyo umbala wamehlo wabazali nabantwana uhambelana, kodwa kukho ukungafani. Ezi ngcaciso zichazwe ziziqulatho ezahlukeneyo ze-melanin - i-pigment ejongene nokubala umbala, iinwele kunye ne-iris. Ngabantu abanamahloni kunye ne-blonde, i-pigment yincinci kakhulu, ayikho i-albinos nonke. Umbala obomvu wamehlo imilambo yegazi, engagqithwanga yi-pigment. Kutheni umbala omnyama we-iris oqhelekileyo? I-Genetics ibonisa ukuba amehlo omdaka awona mbonakalo ophezulu, eluhlaza okwesibhakabhaka kunye nolwempunga. Ngoko ke, ngabazali abanamabala abomdaka, umbala wamehlo omntwana unobuntsundu, kwaye kumama-grey-eyed and daddies, intsana enamehlo amnyama ayinakuzalwa.
Ngaba umntu unokuchaza njani ukuba umbala wamehlo omntwana osandul 'ukuzalwa usoloko unjalo? Oku kungenxa yemisebenzi yamaseli e-melanocyte. Abasebenzi abancinci abazange baqale ngokukhawuleza ukuvelisa i-melanin. Ngokukhawuleza ukuqokelela, i-pigment idonsa iris yamehlo kwimibala efakwe kumzimba. Kwabanye abantwana u-turbidity uqala ukukhula ukukhanya, kwaye ngomnyaka wesiqingatha umntwana ubheka ihlabathi ngeenyawo ezikhanyayo. Kwabanye, ngokuphambene noko, babumnyama. Khumbula ukuba amehlo omntwana angashukunyiswa ngexesha. Kodwa utshintshe umbala omnyama obomvu ukuya kwi-gray okanye eluhlaza okwesibhakabhaka - akakho. Ukwahlukana ngukusebenza kakubi kumsebenzi we-melanocytes.
Ukuphulwa okunjalo kwinkqubo yokuvelisa i-pigment akunqabile, kwaye kufuneka uqaphele abazali. I-Heterochromia - xa iliso elinye linemibala emininzi ngaphezu kweyesibini, inokuzaliswa (iso lonke) okanye inxalenye (inxalenye okanye icandelo le-iris). Ngamanye amaxesha umntu uhlala nombala wamehlo obalaseleyo ebomini bakhe, evakalelwa kukuba, kodwa amatyala xa ukuphulwa okunjalo kuphelisa nge-cataract akuqhelekanga. Ngako oko, abazali abaye baqaphela ukuhlaziywa kwamehlo abo umntwana kufuneka babonise ngokukhawuleza kwi-ophthalmologist.
Bantwana batshintsha nini umbala wamehlo?
Kwiinyanga ezi-3 zokuqala emva kokuzalwa, utshintsho kumbala we-iris akufanele kulindeleke. Uninzi lwamaxesha amaninzi, utshintsho lokugqibela lwenzeka ngunyaka wokuqala wobomi. Kwamanye abantwana - kwixesha elivela kwiinyanga ezintathu ukuya kwezi-6, kwabanye - ukusuka kwiinyanga ezili-9 ukuya kwezi-12. I-hue yamehlo ingatshintsha ngokungabalulekanga, ukufumana umbala wokugqibela ngeminyaka emi-3 okanye emine.
Uyazi njani umbala wamehlo omntwana?
Ukuchonga umbala wamehlo omntwana, izazinzulu zesafuzo zenze itafile ekhethekileyo, ebonisa ipesenti yezikhundla phantsi kweemeko ezinikeziweyo.
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Nangona kunjalo, akukho ngcali ekwazi ukuthetha ngokuqinisekileyo ngama-99% ukuba iris iris iya kuba yintana esandula kuzalwa. Ngaphezu koko, xa kwenzeka utshintsho okanye ukuphazamiseka komsebenzi we-melanocyte, i-genetics ayinamandla.