Wake wazibuza ukuthi amehlo ethu, njengekhamera enhle, agxila kanjani ngokucacile ezintweni ezikude neziseduze? Ingxenye ebaluleke kakhulu yamehlo ethu iyasiza kulo msebenzi omangalisayo. Leyo "ilensi". Namuhla sikhuluma ngale lensi encane, kodwa ewusizo kakhulu.
Iyini ilensi yeso? Masiyiqonde kalula.
Ilensi yeso ifana nelensi ekhamera. Zicabange uthatha isithombe sembali enhle. Ilensi yekhamera iqoqa ukukhanya okuvela embalini, ikugxilise, bese ikuthumelela ku-sensor engemuva kwekhamera. Yilapho-ke kudalwa khona isithombe esicacile.
Ilensi yeso lethu yenza lokhu kanye. Iyisakhiwo esicacile ngokuphelele, esigobile esitholakala ngaphakathi kweliso lethu. Ukukhanya okungena esweni kudlula kule lensi, kugxile endaweni eyodwa, bese kuwela engxenyeni yeso efana nesikrini ebizwa ngokuthi i-retina. Le retina iyinzwa yekhamera esweni lethu. Ukusuka lapho, leyo datha iya ebuchosheni bese siyibona njengesithombe.
Kwenzekani ngempela ngaleli lensi elincane?
Umsebenzi oyinhloko welensi yeso ukugxila . Kodwa lokhu kuyinkimbinkimbi kakhulu kunalokho ongakucabanga.
Zicabange ubheke intaba ekude, bese kuthi ngomzuzwana olandelayo ufunde incwadi esandleni sakho. Ukuze ubone kahle kuzo zombili izindawo, ilensi yeso kufanele ishintshe isimo sayo.
- Uma ubheka kude: ilensi iba yisicaba kancane.
- Uma ubheka eduze: Ilensi iyaphakama kancane bese iba yindilinga.
Leli khono lokushintsha isimo ngokuzenzakalelayo yilona elisivumela ukuthi sibone ngokucacile emabangeni ahlukene. Kodwa khumbula, i-cornea, ingxenye ecacile yeso engaphambili kweso, yenza cishe u-70% wamandla okugxila. Ilensi yenza umsebenzi wokulungisa kahle ama-30% asele.
Iphi ilensi yeso?
Uma ubheka iso lakho esibukweni, ungabona ingxenye enombala yeso (esimweni sethu inombala onsundu/omnyama). Siyibiza ngokuthi i-iris. Ingxenye encane emnyama eyindilinga ephakathi ibizwa ngokuthi i-pupil. Kalula nje, le pupil iwumnyango lapho ukukhanya kungena khona iso.
Ilensi yeso lethu itholakala ngemuva kwale cornea. Lokhu kusho ukuthi ukukhanya kuqala kungena nge-cornea, bese kuwela kulensi, bese kusuka lapho, kugxile kwi-retina.
Le lensi emangalisayo yenziwe ngani?
Ilensi yeso iyindalo emangalisayo ngempela. Yakhiwe uhlobo olukhethekile lweprotheni olubizwa ngokuthi "ama-Crystallins". Ilensi yeso yindawo lapho kukhona khona ukugcwala okuphezulu kweprotheni kunoma yisiphi izicubu emzimbeni wethu. Kungenxa yala maphrotheni akhethekile ukuthi ilensi ithola isimo sayo sokucaca kanye namandla okugxila.
Into ebalulekile ukuthi njengoba amaseli akule lensi evuthwa, alahlekelwa yizingxenye ezifana ne-nuclei yawo. Yingakho ilensi iba sobala ngokuphelele ngaphandle kwesithiyo. Kodwa lokhu kunomphumela omubi. Ngenxa yokuthi ayikho i-nucleus, la maseli awakwazi ukwahlukana futhi akhule amasha. Lokho kusho ukuthi amaseli elensi esinawo lapho sizalwa afana phakathi nokuphila kwethu konke. Amaseli amasha aqoqana ngaphandle, kodwa amaseli amadala ayahlangana phakathi. Njengezindandatho zesiqu somuthi. Ngokuhamba kwesikhathi, amaseli amadala kakhulu phakathi aqala ukuba buthaka.
Izinkinga ngelensi yeso njengoba sikhula (izinhlungu zesikhumba kanye nokukhubazeka kokubona)
Ngokuhamba kwesikhathi, ikakhulukazi ngenxa yokuchayeka elangeni nezinye izici zemvelo, amangqamuzana amadala amaprotheni kulensi yeso lethu aqala ukuwohloka futhi anciphe. Lokhu kubangela ukuthi amangqamuzana alahlekelwe ukukhanya kwawo, abe namafu, futhi abe namafu. Yilokhu esikubiza ngokuthi "ama-Cataract ahlobene nobudala."
Futhi, njengoba sikhula, ilensi ilahlekelwa ukuguquguquka kwayo. Lokhu kusho ukuthi ilahlekelwa ikhono layo lokuba yindilinga uma ibheka eduze. Yilapho izinto eziseduze ziba mfushane, ikakhulukazi lapho kufundwa incwadi noma iphephandaba. Lesi simo sisibiza ngokuthi `(Presbyopia)`.
| Isimo sezokwelapha | Kwenzekani kanye nezimpawu |
|---|---|
| Ama-cataract | Amaprotheni aselensini ayaphuka abe amafu/amaxolo . Umhlaba ubonakala unenkungu futhi ungacacile. I-iris emnyama yeso ibonakala ingwevu noma imhlophe. |
| I-Presbyopia | Ubunzima bokubona eduze ngenxa yokuncipha kokuguquguquka kwelensi. Ukufundwa kwezinto ezifana nephephandaba noma incwadi ukude. Ukucindezeleka kwamehlo lapho usebenza eduze. |
Ibukeka kanjani i-cataract uma yakheka?
Uma kuvela ama-cataract, umhlaba ubukeka sengathi ubheka ngengilazi engcolile. Konke kubonakala kufiphele futhi kunenkungu. Ekuqaleni, lokhu kufiphala kungaqala endaweni encane, futhi ngokuhamba kwesikhathi, kungasakazekela kulo lonke ilensi. Kumuntu ongaphandle, i-puppy emnyama ephakathi kweso ingase ibonakale imhlophe qhwa esikhundleni sokuba mnyama. (Ngezinye izikhathi, ngenxa yezizathu zofuzo, izingane zizalwa zine-cataract, futhi lokhu kungenye yezimpawu eziyinhloko ezingakusiza ukuthi uzibone.)
Ukubona Okuseduze (i-Presbyopia)
Njengoba ukuguquguquka kwelensi kuncipha, kuba nzima ngawe ukugxila ezintweni eziseduze nawe. Kungenzeka ukuthi uke wababona asebekhulile emakhaya ethu befunda iphephandaba belule izingalo zabo futhi bekude. Lesi yisona sizathu salokhu. Noma, lapho ufunda incwadi noma ubheka ifoni, amehlo akho angase azizwe ekhathele ngokushesha.
Yiziphi izindlela zokwelapha lezi zimo?
Manje kunezindlela zokwelapha eziphumelela kakhulu zombili lezi zinkinga, ngakho-ke asikho isizathu sokwesaba.
Into ebaluleke kakhulu ukuthi uma ubona noma yiziphi izinguquko ekuboneni kwakho, bonana nodokotela ofanelekayo ngokushesha okukhulu bese uhlolwa amehlo akho.
Ukwelashwa kokubona eduze (i-Presbyopia)
Njengoba lesi kuyisimo esivamile esenzeka ngokweminyaka, kunezixazululo eziningana:
- Izibuko: Ukugqoka izibuko ezinamandla afanele kuyindlela elula nevame kakhulu.
- Ama-Contact Lens: Lena inketho enhle kulabo abangathandi izibuko.
- Amaconsi Eso: Eminye imithi yesimanje ingathuthukisa okwesikhashana ukubona eduze ngezinga elithile.
- Ukuhlinzwa Kokulungisa Umbono: Lesi simo singalungiswa ngezindlela ezinjengokwelashwa nge-laser.
Udokotela wakho uzohlola isimo samehlo akho futhi akuchazele ukuthi yikuphi ukwelashwa okungcono kakhulu kuwe.
Ukwelashwa kwe-cataracts
Ukwelashwa okuwukuphela futhi okuphumelelayo kakhulu kwe-cataracts ukuhlinzwa. Lokhu manje sekuyindlela yokuhlinzwa evame kakhulu futhi ephephile emhlabeni.
Lokhu kuhilela udokotela ohlinzayo ukususa ilensi yakho yemvelo enamafu bese eyishintsha ngelensi yokwenziwa (Intraocular Lens, noma i-IOL) . Lokhu kuyindlela yokwelapha ephumelela kakhulu, futhi abantu abaningi baphinde babone kahle ngemva kokuhlinzwa.
Ngezinye izikhathi, ngaphambi kokuba kuvele ama-cataract, lolu hlobo lokuhlinzwa kokufakelwa kwelensi yokwenziwa lwenziwa ukuze kulungiswe izinkinga zokubona eziseduze/ezikude. Lubizwa ngokuthi `(Refractive Lens Exchange)`.
Singawavikela kanjani amalensi amehlo ethu?
Nakuba singenakukuyeka ukuguga, kunezinto eziningana esingazenza ukuvimbela ilensi emehlweni ethu ukuba ingabi buthaka ngokushesha futhi inciphise umonakalo.
- Ukuvikelwa kwelanga: Imisebe ye-ultraviolet ekukhanyeni kwelanga okunamandla iyingozi kulensi yeso. Ngakho-ke, gqoka izibuko zelanga zekhwalithi enhle uma uphuma elangeni.
- Gwema ukubhema: Ukubhema kanye nokuchayeka entuthwini yokubhema kwandisa kakhulu ingozi yokuthola ama-cataract.
- Ukulawulwa kwesifo sikashukela: Uma unesifo sikashukela, kubaluleke kakhulu ukusilawula kahle, njengoba isifo sikashukela esingalawulwa siyinto enkulu ebangela ama-cataract.
- Ukuhlolwa kwamehlo njalo: Ukuhlolwa kwamehlo ngudokotela njalo, ikakhulukazi ngemva kweminyaka engu-40, kungasiza ekuboneni noma yiziphi izinkinga kusenesikhathi futhi kufune ukwelashwa.
Ilensi yeso lethu iyisakhiwo esiyingqayizivele esibalulekile ukuze sibone kahle. Kuvamile ukuthi ishintshe ngokuhamba kwesikhathi. Kodwa-ke, uma sikuqaphela futhi sinakekela kahle amehlo ethu, singabona umhlaba ngokucacile kukho konke ukuphila kwethu.
Umlayezo Wokuya Nawe Ekhaya
- Ilensi yeso ifana nelensi yekhamera, ingxenye esiza ukugxila ekukhanyeni nokudala isithombe esicacile.
- Njengoba sikhula, ilensi iba namafu (cataracts) futhi ukuguquguquka kwayo kuncipha (presbyopia). Lezi yizimo ezivamile.
- Ukwelashwa okuwukuphela kwe-cataracts ukuhlinzwa ukuze kususwe ilensi enamafu bese kufakwa ilensi yokwenziwa. Kuyindlela yokwelapha ephumelela kakhulu futhi ephephile.
- Ukwelashwa okufana nezibuko, ama-contact lens, noma ukuhlinzwa kungasetshenziswa ukulungisa ukubona eduze.
- Ukugqoka izibuko zelanga, ukugwema ukubhema, nokulawula izifo ezifana nesifo sikashukela kungasiza ekugcineni impilo yelensi yakho yamehlo isikhathi eside.
- Uma ubona noma yiziphi izinguquko embonweni wakho, funa iseluleko sezokwelapha ngokushesha.
💬 Comments (0)
Awekho amazwana athunyelwe okwamanje. Faka amazwana akho lapha okokuqala ngqa.
Engeza amazwana akho