Iyo iris ndeye optical system yeziso, inogadzirisa huwandu hwechiedza chinopfuura nemudzidzi. Inhengo yeziso ine ruvara.

Iyo iris chinhu chegirobhu reziso, ndeye vascular tunic (yepakati layer). Inowanikwa pamberi peziso, pakati pe cornea ne lens, mukuenderera mberi kwechoroid. Inobayiwa pakati payo nemudzidzi izvo zvinoita kuti chiedza chipinde muziso. Inoshanda pahupamhi hwemudzidzi nekuita kwe denderedzwa yakatsetseka tsandanyama (sphincter muscle) nemaranzi (dilator muscle).

Pupil control

Iyo iris inosiyanisa kuvhurwa kwemudzidzi nekukochekera kana kuwedzera sphincter uye dilator tsandanyama. Kufanana nediaphragm iri mukamera, nokudaro inodzora kuwanda kwechiedza chinopinda muziso. Kana ziso richiona chinhu chiri pedyo kana chiedza chakajeka, sphincter muscle contracts: mudzidzi anoomesa. Kusiyana neizvi, kana ziso richiona chinhu chiri kure kana chiedza chisina simba, dilator muscle zvibvumirano: mudzidzi anowedzera, dhayamita yaro inowedzera uye inoita kuti chiedza chipfuure.

Mavara eziso

Muvara weiris unoenderana nehuwandu hwe melanin, brown pigment, iyo inowanikwawo muganda kana bvudzi. Iyo yakakwirira yekuisa pfungwa, maziso anosviba. Maziso ebhuruu, girini kana hazel ane zviri pakati pepakati.

Aniridie : inokonzeresa kusavapo kweiris. Kuremara kwemajini kunoonekwa pakuzvarwa kana muhuduku. Rare pathology, inokanganisa 1 / 40 kuberekwa pagore. Chiyero chechiedza chinopinda muziso hachidzorwi: chakawandisa, chinogona kukuvadza zvimwe zvimiro zveziso. Aniridia inogona kuomeswa necataract kana glaucoma, semuenzaniso.

Albinism yemaziso : genetic chirwere chinoratidzwa nekusavapo kana kuderedzwa kwe melanin muiris uye retina. Muchiitiko ichi, iris inotaridzika yebhuruu kana grey ine tsvuku inopenya pupil nekuda kwetsinga dzeropa dzinoonekwa mukujeka. Uku depigmentation imhaka yekusavapo kana kushomeka kwe tyrosinase, enzyme inobatanidzwa mukugadzirwa kwe melanin pigments. Zviratidzo zvinowanzoonekwa ndezvi:

• nystagmus: kufamba-famba kwemaziso
• photophobia: kusashivirira kwemaziso kuchiedza zvinogona kukonzera kurwadziwa kwemaziso
• kuderera kwekuona acuity: myopia, hyperopia kana astigmatism inogona kukanganisa vanhu vane albinism.

Iyi depigmentation inogonawo kukanganisa ganda nevhudzi, tinotaura nezve oculocutaneous albinism. Chirwere ichi chinokonzera ganda rakanaka uye bvudzi rakacheneruka rakachena kana blond.

HeteroChromia : inowanzonzi "wall eyes", haisi chirwere asi chimiro chemuviri chinoguma nechikamu kana mutsauko wakazara muvara weiris. Inogona kukanganisa irises yemaziso ose uye inooneka pakuberekwa kana inogona kubva kune chirwere chakadai se cataract kana glaucoma.

Heterochromia inogona kukanganisa imbwa uye katsi. Pakati pevanozivikanwa, David Bowie anowanzo kurondedzerwa seane maziso akasviba. Asi ruvara rwebrown muziso rake rekuruboshwe rwakakonzerwa nechirwere chemydriasis chechigarire, mugumisiro wekurohwa kwaakaitwa mumakore ake okuyaruka. Mydriasis ndiko kuwedzera kwechisikigo kwemudzidzi murima kuitira kuunza mwenje wakawanda sezvinobvira muziso. Kuna Bowie, mhasuru dziri muiris yake dzakakuvadzwa nekurova kwakaita kuti mudzidzi wake awedzere zvachose uye achinje ruvara rweziso rake.

Hapana marapiro ezvirwere izvi. Kuvhenekwa nezuva kwevanhu vane albinism kunogona kukonzera kukuvara kweganda uye njodzi yavo yegomarara reganda yakakura. Sangano reWorld Health Organisation (WHO) (6) rinopa zano rekuti usambozvifumura kuchiedza chezuva, kubva paudiki. Kupfeka ngowani nemagirazi ezuva kunokurudzirwa sezvo iris ine ruvara rusingachaiti basa rayo sechipinganidzo pamwaranzi yeultraviolet yezuva.

Iridologie : chaizvoizvo "kudzidza kweiris". Iyi tsika inosanganisira kuverenga uye kududzira iris kuona mamiriro emuviri wedu uye kuita cheki yehutano. Iyi nzira yakakwikwidzwa haina kumbobvira yakasimbiswa nesainzi nekutsvagisa.

Biometrics uye iris identification

Iris imwe neimwe ine chimiro chakasiyana. Mukana wekuwana irises mbiri dzakafanana ndeye 1/1072, nemamwe mazwi hazvigoneke. Kunyange mapatya akafanana ane irises yakasiyana. Hunhu uhu hunoshandiswa nemakambani ebiometric ayo ari kugadzira hunyanzvi hwekuziva vanhu nekuziva matinji avo. Nzira iyi yava kushandiswa munyika yose nevanoona nezvekubuda kwezvinhu, mumabhanga kana mumajeri (8).

Sei vana vane maziso ebhuruu?

Pakuzvarwa, melanin pigments inovigwa mukati meiris (9). Rudzi rwayo rwakadzika, rwuri rweblue-grey muruvara, rwunobva rwaonekwa pachena.

Ichi ndicho chikonzero vamwe vana vane maziso ebhuruu. Kwemavhiki, melanin inogona kukwira kumusoro kweiris uye kuchinja ruvara rwemaziso. Deposit pamusoro pe melanin inokonzeresa maziso ebrown nepo ikasasimuka, maziso anoramba ari bhuruu. Asi chiitiko ichi hachikanganisi vacheche vese: vacheche vazhinji vemuAfrica neAsia vanotova nemeso matema pavanozvarwa.

Maziso ebhuruu, genetic evolution

Pakutanga, varume vese vaive nemeso ebrown. Kuchinja kwemajini kwakangoerekana kwakanganisa jini rimwe chete reruvara rweziso, uye maziso ebhuruu akaonekwa. Sekureva kwechidzidzo chegumi (10), shanduko iyi yakaonekwa makore 2008 kusvika gumi apfuura uye yakabva kuna tateguru mumwe. Kuchinja uku kwaizobva kwapararira kuvanhu vese.

Dzimwe tsananguro dzinogonekawo, zvisinei: shanduko iyi yaigona kunge yakaitika kakati wandei yakazvimiririra, isina kwainotangira, kana kumwe kuchinja kunogona kukonzera maziso ebhuruu.