I ka hānau ʻana, loaʻa nā maka polū-hinahina ka nui o nā pēpē. Akā ʻaʻole i pau kēia kala. He mau mahina e ʻike maopopo ai inā loaʻa iā lākou nā maka o ko lākou makuakāne, ko lākou makuahine, a i ʻole kekahi o ko lākou mau kūpuna.

Hoʻomaka ka hana ʻana o ka optical apparatus o ka fetus mai ka lā 22nd ma hope o ka hāpai ʻana. I loko o ka mahina ʻelua o ka hāpai ʻana, ʻike ʻia kona mau lihilihi, e paʻa mau ana ka sila a hiki i ka mahina ʻehiku o ka hāpai ʻana. A laila hoʻomaka kona mau maka maka e neʻe mālie a ʻike wale i nā ʻokoʻa o ka mālamalama.

Ma muli o ka hoʻohana liʻiliʻi ʻana, ʻo ka ʻike ka mea liʻiliʻi loa i hoʻomohala ʻia i loko o ka pēpē: ʻo kāna ʻōnaehana ʻike ka mea hope loa e hoʻokomo ʻia, ma hope o ka ʻōnaehana auditory, olfactory a tactile paha. ʻO kēlā me kēia ʻaoʻao, ua mākaukau nā maka o ka pēpē e hele mai ka hānau ʻana. ʻOiai e hala ana lākou i kekahi mau mahina ma mua o ka ʻike ʻana e like me ke kanaka makua.

I ka hānau ʻana, loaʻa nā maka hina polū ka hapa nui o nā keiki no ka mea ʻaʻole i hoʻāla ʻia nā puaʻa kala ma ka ʻili o ko lākou iris. No laila ʻo ia ka papa hohonu o ko lākou iris, ʻeleʻele uliuli maoli, ʻike ʻia i ka ʻike. ʻO nā pēpē no ʻApelika a me ʻAsia, ma kekahi ʻaoʻao, he mau maka ʻeleʻele ko lākou mai ka hānau ʻana.

I loko o nā pule mua, e hōʻike mālie nā ʻili puaʻa ma ka ʻili o ka iris iā lākou iho a waiho i kona kala, a hiki i ka wā e hāʻawi ai i kona kala hope. Ma muli o ka nui o ka melanin, ʻo ia ka mea e hoʻoholo ai i ke kala o kona ʻili a me kona lauoho, ʻeleʻele a ʻeleʻele paha nā maka o ka pēpē, ʻoi aku ka māmā a i ʻole ka ʻeleʻele. ʻO nā maka hina a me nā ʻōmaʻomaʻo, ʻaʻole maʻamau, ua manaʻo ʻia he mau aka o kēia mau kala ʻelua.

Hoʻoholo ʻia ke ʻano o ka melanin, a no laila ke kala o ka iris. Ke loaʻa nā maka ʻeleʻele a ʻōmaʻomaʻo paha nā mākua ʻelua, hiki i kā lāua keiki ma kahi o 75% ka loaʻa ʻana o nā maka ʻeleʻele a ʻōmaʻomaʻo pū kekahi. Ma ka ʻaoʻao ʻē aʻe, inā he mau maka uliuli ko lāua ʻelua, hiki iā lāua ke maopopo loa e mālama ka pēpē i nā maka uliuli i hānau ʻia no ke ola. Pono ʻoe e ʻike he "dominant" ka kala ʻeleʻele. ʻO ka pēpē me hoʻokahi makua me nā maka ʻeleʻele a ʻo kekahi me nā maka uliuli e loaʻa pinepine i ka malu ʻeleʻele. ʻO ka hope, hiki i nā mākua ʻelua me nā maka ʻeleʻele ke loaʻa i kahi pēpē me nā maka uliuli, ʻoiai he mau maka uliuli kekahi o kona mau kupuna.

Ma waena o 6 a me 8 mahina e ʻike ai i ke kala hope o nā maka o ka pēpē.

ʻElua mau maka o ke kanaka hoʻokahi. ʻO kēia hiʻohiʻona, i ʻike ʻia ma lalo o ka inoa o "maka paia", e lawe i ka inoa ʻepekema o heterochromia. Ke loaʻa kēia heterochromia mai ka hānau ʻana, ʻaʻohe hopena i ke olakino a i ʻole ka ʻike maka o ka mea nāna e hoʻohana. Inā loaʻa ia ma hope o kahi ʻeha, a i ʻole me ke kumu ʻike ʻole, pono ia i kahi kūkākūkā olakino no ka mea hiki ke hōʻailona o kahi hōʻeha.