Pakuberekwa, vana vakawanda vane maziso ebhuruu-grey. Asi ruvara urwu haruna kupera. Zvichatora mwedzi yakati kuti kuziva zvechokwadi kana pakupedzisira vachizova nemaziso ababa vavo, amai vavo, kana kuti kunyange mumwe wasekuru naambuya vavo.

Chigadzirwa chemaziso che "fetus" chinotanga kuumbwa kubva pazuva rechimakumi maviri nemaviri mushure mekubata pamuviri. Mumwedzi wechipiri wekudzivirira, maziso ake anooneka, ayo acharamba akavharwa kusvika pamwedzi wechinomwe wepamuviri. Maziso ake anobva atanga kufamba zvishoma nezvishoma uye achiita seanongonzwa nekusiyana kwechiedza.

Nekuda kwekuti haishandiswe zvishoma, kuona ndiyo pfungwa isina kusimba mumwana mudumbu: hurongwa hwayo hwekuona ndiyo yekupedzisira kuiswa panzvimbo, mushure mekunzwa, kunhuwa kana kubata. Chero zvazvingava, maziso emwana anenge agadzirira kubva pakuzvarwa. Kunyangwe zvikazovatorera imwe mwedzi yakati wandei vasati vaona semunhu mukuru.

Pakuzvarwa, vana vazhinji vane maziso ebhuruu egrey nekuti mavara ane mavara ari pamusoro peiris yavo haasati aitwa. Naizvozvo ndiyo yakadzika danga reiris yavo, yakasikwa yebhuruu grey, iyo inoonekwa mukujeka. Vacheche veAfrica neAsia, kune rumwe rutivi, vane maziso erima kubva pakuberekwa.

Mumavhiki mashoma ekutanga, masero epigment aripo pamusoro peiris anozozviratidzira zvishoma nezvishoma uye nekuipenda, kusvikira aipa iyo yekupedzisira ruvara. Zvichienderana nehuwandu hwe melanin, iyo imwechete iyo inosarudza ruvara rweganda rake nebvudzi, maziso emwana achava bhuruu kana shava, zvishoma kana zvishoma chiedza kana rima. Meso e grey uye girinhi, asinganyanyi kuwanda, anoonekwa semumvuri weaya mavara maviri.

Iko kusanganiswa kwe melanin, uye naizvozvo ruvara rweiris, inotarirwa genetically. Kana vabereki vaviri vaine maziso ebrown kana egirinhi, mwana wavo ane mukana we75% wekuve nemaziso ebrown kana egirinhi zvakare. Kune rumwe rutivi, kana vose vari vaviri vane maziso ebhuruu, vanogona kuva nechokwadi chokuti mwana wavo acharamba aine maziso ebhuruu aakaberekwa nawo kwoupenyu hwose. Iwe unofanirwa kuziva zvakare kuti iyo brown color inonzi "inotonga". Mwana ane mubereki mumwe ane maziso ebrown uye mumwe ane maziso ebhuruu anowanzogara nhaka mumvuri wakasviba. Pakupedzisira, vabereki vaviri vane maziso ebrown vanogona kuva nemwana ane maziso ebhuruu, chero bedzi mumwe wasekuru vake pachake ane maziso ebhuruu.

Zvinowanzotora pakati pemwedzi mitanhatu ne6 kuti uzive ruvara rwekupedzisira rwemaziso emwana.

Zvinoitika kuti munhu mumwe chete ane maziso emavara maviri. Ichi chiitiko, chinozivikanwa pasi pezita re "wall eyes", ine zita resainzi reheterochromia. Kana iyi heterochromia iripo kubva pakuzvarwa, haina mhedzisiro pahutano kana kuona kweanoripfeka. Kana zvikaitika mushure mekushungurudzika, kana kunyange pasina chikonzero chakajeka, zvinoda kubvunzurudzwa kwechiremba nokuti inogona kuva chiratidzo chekukuvara.