Ukungaboni Imibala Ukukhubazeka Okuyinqaba
YEKA ukuthi bashaqeka kanjani abakwa- Quaker lapho bebona amasokisi kaJohn Dalton abomvu klebhu! Njengoba ayevame ukugqoka imibala ezothile—empunga, ensundu, nomnyama—kafushane nje, bathola amasokisi kaJohn eshaqisa. Kwakwenzekeni?
UDalton, owazalelwa e-Eaglesfield, eNgilandi ngo-1766, wachaza igazi ngokuthi “liluhlaza ngokukhanyayo” (bottlegreen) futhi wathi icembe lomnyezane “lalifana kahle nenhlaka [ebomvu] yokunamathisela.” Yebo, uDalton owaba umthaki wemithi odumile, wayenesifo sokungaboni imibala, noma ngokuthe ngqó, ukukhubazeka kokungaboni imibala.
KuDalton, umbala obomvu wawubukeka njengompunga futhi wawuhluke kancane nje koluhlaza okotshani. Akumangalisi ukuthi umngane wakhe owenza amahlaya angokoqobo waphambanisa amasokisi akhe futhi wabangela lokhu kushaqeka! Ngokuthakazelisayo, kwamanye amazwe aseYurophu, ukungaboni imibala kwaziwa ngokuthi iDaltonism.
Inkinga Yomhlaba Wonke
Ngo-1980, uDkt. Janet Voke waseCity University, eLondon, walinganisela ukuthi abantu abangaphezu kwezigidi ezimbili eBrithani banokukhubazeka kokungakwazi ukubona imibala. Kweminye imiphakathi engayodwa, abambalwa uma kuqhathaniswa abahlushwa yilenkinga. EFiji, indoda eyodwa kuphela kwangu-120 engayiboni imibala, kuyilapho eCanada, indoda eyodwa kwangu-9, ngokwesilinganiso, eyibona kancane imibala.
Ukubona imibala kuyehlukahluka kubantu ngabanye. Ngokombono owamukelwa kabanzi, ubona kahle uma ubona umbala omhlophe lapho imisebe emithathu yokukhanya—owodwa kwebomvu ngaminye, oluhlaza okotshani, noluhlaza okwesibhakabhaka—ihlanganiswa ngezilinganiso ezilinganayo. Lapho imisebe emithathu ihlanganiswa ngezilinganiso ezihlukahlukene, kungavezwa eminye imibala okwaziyo ukuyibona ngokwemvelo.
Nokho, uma yonke imibala okwaziyo ukuyibona ingahlanganiswa nemibili kuphela yalemibala eyinhloko, futhi ukunezelwa kowesithathu kungenzi mehluko ophawulekayo, khona-ke ukubona kwakho imibala kukhubazekile. Ungumuntu obona imibala emibili kuphela (idichromat). UJohn Dalton wayebona imibala emibili kuphela engawuboni obomvu.
Ukukhubazeka okuthinta labo ababona umbala owodwa kuphela (amamonochromat) kungokungathi sína kakhulu. Labo abanalesisimo abakwazi ukuhlukanisa imibala. Kubantu abakwazi ukubona umbala owodwa kuphela, iTV enombala ogqamile ingase ifane nje nenombala owodwa.
Iningi labantu abangakwazi ukubona imibala bangabantu abangajwayelekile abakwazi ukubona imibala exutshwe yaba mithathu (amatrichromat). Imibala ebonakalayo kulabantu iyimibala exube yonke imibala emithathu eyinhloko, kodwa abantu ababona imibala emithathu abangavamile bayehluka ngezilinganiso zemibala eyinhloko abakwazi ukuyibona. Uma lokhu kuyinkinga yakho, ukulungisa iTV ukuze igqame kahle ngokwendlela obona ngayo ukuhlangana okuhle kwemibala kungenza abantu bakhale ngokuthi “Ibomvu kakhulu!” noma “Iluhlaza kakhulu!”
Izimbangela
Yini ebangela lokho kukhubazeka? INew Encyclopædia Britannica ichaza enye imbangela ngokuthi “ithuluzi lakho lokubona ukungafani kwebanga lamaza.” Iso lakho ngalinye linezinzwa ezamukela ukukhanya eziyizigidi ezingu-130 kuyiretina, kodwa eziyizigidi ezingu-7 kuphela kulezi ezenza ukwazi ukubona imibala. Lezinzwa zemibala zibizwa ngokuthi amacone ngenxa yokumisa kwazo okwamacone.
Abantu abayibona kahle imibala banezinhlobo ezintathu zamacone. Amanye amacone asabela kangcono kakhulu emabangeni amade amaza okukhanya (umbala obomvu). Iqembu lesibili lizwela emabangeni aphakathi amaza (umbala oluhlaza okotshani), futhi wonke amanye azwela emabangeni amafushane amaza (umbala oluhlaza okwesibhakabhaka). Uma iqembu elithile lamacone lingekho noma lehluleka ukusabela ngokufanelekile ebangeni lamaza elisebenzelana nalo, uyoba nenkinga. Ngokwesibonelo, uma wehluleka ukuwubona kahle umbala obomvu, uyophawula umehluko omncane kakhulu lapho utamatisi uvuthwa usuka ekubeni luhlaza uya embaleni osawolintshi kulandele obomvu.
Ukulimala kwenzwa enkulu yamehlo (optic nerve) okuphazamisa umbiko ohanjiswa amacone engqondweni kungabangela ukungayiboni imibala. Ngisho nezinhlobo ezithile zokwelapha, njengamaphilisi athile anqanda umalaleveva, aye aziwa njengaphazamisa ukubona imibala. Amanye amaphilisi okuvimba inzalo kubikwa ukuthi angashintsha ukubona imibala eluhlaza okwesibhakabhaka, oluhlaza okotshani, kanye nophuzi. Encwadini ethi Colour Vision Testing, uDkt. Voke ubala kokubili ugwayi notshwala njengokuyimbangela yokunye ukungawuboni umbala obomvu noluhlaza okotshani.
Ukuguga nakho kufeza ingxenye yakho, ikakhulukazi ekuzweleni komuntu ekukhanyeni okuluhlaza okwesibhakabhaka. Umcwaningi uR. Lakowski uthi ukuhlukanisa imibala kufinyelela iqophelo eliphezulu ngesikhathi sokweva eshumini elinambili, futhi kuhlala kuze kufinyelele eminyakeni engu-35. Khona-ke, ukuhlukanisa komuntu imibala kuyawohloka kancane kancane, ikakhulukazi ngemva kweminyaka engu-60 yobudala.
Nakuba ukubona imibala okukhubazekile kungase kube khona phakathi nesikhathi sokuphila komuntu, abaningi balabo abangayiboni imibala bazalwa benjalo. Ngani?
‘Ukhamba Lufuze Imbiza’
Ukubona kahle imibala komuntu kuyisipho esikhethekile. Uma amacone akho esebenza kahle futhi izinzwa zakho ezinkulu zamehlo ziyidlulisela kahle engqondweni imibiko eziyiphathisiwe, khona-ke uyibona kahle yonke imibala. “Iso lomuntu eliqeqeshiwe lingahlukanisa imibala eminingi efinyelela kwengu-150,” kubika incwadi iHow Animals See. “Izilwane eziningi . . . ngokunokwenzeka aziyiboni imibala ngendlela esiyibona ngayo. Kodwa lesimo singokwemvelo emehlweni azo, akukhona ukukhubazeka,” kusho iWorld Book Encyclopedia.
Uma indlela obona ngayo ibilokhu ingeyinhle, ngokungangabazeki lesici wasithola ngofuzo. Kubani? IHealth and Disease ichaza ukungaboni imibala njengesifo samangqamuzana ofuzo “esihlobene nobulili esidluliselwa abesifazane kodwa ngokuvamile bese sivela kubantu besilisa ezizukulwaneni ezihlukahlukene.” Ngakho-ke, ngokuvamile, ‘ukhamba lufuza imbiza.’
Awuyiboni Imibala? Indlela Yokwazi
Ingabe usola ukuthi izingane zakho azikwazi ukubona imibala? “Uma uphawula ukuthi ingane yakho eneminyaka eyisi-5 noma eyisi-6 ubudala inobunzima bokuhlukanisa imibala; uma igqoka amasokisi angahambelani; noma uma ingakwazi ukuthatha ipeni elifanele ebhokisini lapho icelwa ukuba ilikhethe ngombala,” khona-ke, incwadi iChildcraft ithi, “kufanele uqikelele ukuba amehlo ayo ahlolwe.” Kanjani?
Enye yezindlela ezijwayeleke kakhulu zokuhlola ukubona imibala i-Ishihara test. Udokotela ohlolayo ubonisa ingane yakho inqwaba yamakhadi anamachashaza emibala eminingi ehlukahlukene. Phakathi kwalamachashaza kuhlelwe imidwebo nezinombolo ezibonakala kunoma ubani oyibona kahle imibala. Ingane yakho kufanele isho ukuthi umdwebo onjani noma umfanekiso onjani ewubonayo. Ibheke eshadini elilodwa, ingane engakwazi ukuwubona umbala obomvu ibona u“6,” ingane engawuboni umbala oluhlaza okotshani ibona u“9.” Uma ingane yakho ibona u“96,” ngokwaleyo ngxenye yokuhlola iyibona kahle imibala.”
Njengoba ukusetshenziswa kwemibala ezintweni ezisetshenziselwa ukufundisa izingane kwanda njalo, kuhlakaniphile ukwazi ukuthi ukubona kwezingane zakho imibala akukhubazekile yini. Kodwa njengoba ukungayiboni imibala okutholwe ngofuzo okwamanje kungenakushintshwa futhi kungelapheki, ingabe kukhona ongakwenza ngakho?
Izinyathelo Zokuphepha Okumelwe Zithathwe
UHazel Rossotti, umlobi wencwadi iColour, utusa kuqala ukuhlolwa kungakephuzi. Khona-ke umuntu ongayiboni imibala “angaqasheliswa ngezimo okungenzeka zibangele ukudideka futhi afundiswe ukuba noma nini lapho kungenzeka khona encike ezicini kunasemibaleni edidayo.”
Ungayifundisa ingane yakho engayiboni imibala lokho okushiwo izimpawu zomgwaqo ezinemibala. Nakuba ingase ikwazi ukuhlukanisa ilambu elibomvu lokumisa kweliluhlaza elisho ukuthi “hamba” ngokwezindawo ezikuyo ngokulandelana, yisize ukuba iqaphele ukungefani kokugqama kokukhanya ngakunye. Khona-ke, lapho iyodwa, iyozifunda kahle izimpawu ngisho nasebumnyameni.
Uma ungakwazi ukubona imibala, kuhle ukugwema ukuthembela embaleni kuphela lapho wenza izinqumo. Njengoba ingqondo ingawenza umsebenzi wamehlo anokukhubazeka kokungayiboni imibala, gcwalisa inqolobane yayo yokwaziswa ngokuqaphelisisa ukugqama kwento, indawo ekuyo, nokuma kwayo. Unganqikazi ukucela abangane nezihlobo abayibona kahle imibala ukuba bakusize.
Ekwenzeni izinqumo ezibalulekile, njengohlobo lomsebenzi ozowenza, uyobe wenza ngokuhlakanipha uma uqaphela imiphumela emibi ukukhubazeka kokungayiboni imibala okungayiletha. Kweminye imisebenzi, ukungayiboni imibala kungaba isici esibi kakhulu. Ngokwesibonelo, kuyisithiyo emakhemisi amaningi, abathaki bemithi, abashicileli ababhala ngemibala egqamile, kanye nabathwebuli bezithombe. Ukubona kahle imibala kuyinzuzo kodokotela bamazinyo lapho befanelanisa amazinyo okufakelwa. Futhi, izilaha kanye nalabo abanezimboni ezidayisa ukudla okuphekiwe zingaqapha ngokwengeziwe ezinguqukweni zesimo sokudla lapho zikwazi ukuyibona kahle imibala. Ukungakwazi ukubona imibala kungenza kube nzima ngokwengeziwe ngabahlengikazi nodokotela ukuthola isimo sempilo yeziguli zabo lapho bezipopola.
Noma ubani obona kahle unento ewusizo kakhulu. Uma ukubona kwakho imibala kungaphelele, kufanele wenze ukuqapha okuthile okukhethekile. Ngokwesibonelo, kufanele uqaphele ukuthi ukusebenzisa izidakamizwa ezingadingekile, ukuphuza utshwala ngokweqile, noma ukubhema kungabangela ukuwohloka kokubona imibala. Uma uyibona ngokuphelele imibala, khona-ke unesipho esiyigugu ngokungenakuqhathaniswa.