Ingabe Yaklanywa?

I-retina Ehlanekezelekile

● Iso lomuntu line-retina—ulwelwesi olunamangqamuzana angaba izigidi ezingu-120 abizwa ngokuthi i-photoreceptors, akwazi ukudonsa imisebe yokukhanya abese eyiguqula ibe amaza kagesi. Ubuchopho bakho bushintsha la maza abe izithombe. Abakholelwa ekuziphendukeleni kwemvelo bagomela ngokuthi indawo i-retina ekuyo ezilwaneni ezinomgogodla, ifakazela ukuthi iso alinaye umklami.

Cabangela lokhu: I-retina yezilwane ezinomgogodla ihlanekezelekile, okwenza ama-photoreceptors abe sengxenyeni engemuva. Ukuze kufinyelele kuwo, ukukhanya kufanele kudlule amangqamuzana amaningana. Ngokwesazi sokuziphendukela kwemvelo uKenneth Miller, “lokhu kwakheka kuyakusabalalisa ukukhanya, okwenza izinga lethu lokubona lingacaci ngendlela obekufanele libe ngayo.”

Ngakho-ke, izazi zokuziphendukela kwemvelo zithi, i-retina ehlanekezelekile iwubufakazi bomklamo wezinga eliphansi—empeleni, ayizange iklanywe. Esinye isazi sesayensi saze sayichaza ngokuthi “umklamo osebenzayo kodwa owakheke ngendlela ewubuwula.” Nokho, ucwaningo olwengeziwe lwembula ukuthi ama-photoreceptors e-retina ehlanekezelekile abekeke endaweni efanele eduze kwamangqamuzana adlulisa umoya-mpilo nezakhi ezibalulekile ekuboneni kahle (pigment epithelium). “Ukube la mangqamuzana ayebekwe ngaphambi kwe-retina ikhono lokubona laliyokhinyabezeka kakhulu,” kwabhala isazi sezinto eziphilayo, uJerry Bergman noJoseph Calkins ongudokotela wamehlo.

I-retina ehlanekezelekile, iwusizo ngokukhethekile ezilwaneni ezinomgogodla ezinamehlo amancane. URonald Kröger onguprofesa enyuvesi yaseLund, eSweden uthi: “Phakathi kolwelwesi olungaphambili esweni nama-photoreceptors, kumelwe kube khona isikhala esithile ukuze sibone ngokucacile. Ukugcwaliswa kwalesi sikhala ngamangqamuzana ezinzwa kuwukonga okukhulu ezilwaneni ezinomgogodla.”

Ngaphezu kwalokho, njengoba amangqamuzana ezinzwa e-retina enqwabelene futhi eseduze nama-photoreceptors, ukuhlaziywa kwezinto esizibonayo kuyashesha futhi kuthembekile.

Ucabangani? Ingabe i-retina ehlanekezelekile iyinto nje engabalulekile, into eyaba khona ngengozi? Noma ingabe yaklwanywa?

[Umdwebo ekhasini 15]

(Ukuze ubone ukuthi indaba ihlelwe kanjani, bheka encwadini)

Amangqamuzana e-“photoreceptor”

Ukukhanya

I-“pigment epithelium”

Ukukhanya

I-“retina”

Inzwa yokubona