Ungayifumana njani inani elichanekileyo leeglasi zamehlo? Masithethe ngeRetinoscopy!

Ngaba wakha wahlolwa amehlo? Xa usiya, ugqirha uyakubuza, "Ngaba oku kucacile?", "Ngaba oku kungcono kunangaphambili?" Inani leeglasi zethu limiselwa ziimpendulo esizinikayo. Kodwa ngaba wakha wazibuza ukuba ungazifumana njani iiglasi ezininzi zosana olungakwaziyo ukuthetha kakuhle, okanye zomntu olahlekelwe yinkumbulo yakhe ngenxa yokwaluphala? Yiyo loo nto uvavanyo esithetha ngalo namhlanje, olubizwa ngokuba yi-'Retinoscopy', lubaluleke kangaka.

Ngamafutshane, yintoni i-'Retinoscopy'?

I-retinoscopy luvavanyo olukhethekileyo oluvumela ugqirha wamehlo ukuba alinganise ngokuchanekileyo iimpazamo zokuchasana emehlweni akho. Basebenzisa isixhobo esikhethekileyo esiphathwa ngesandla kunye nokukhanya okuboniswa ngasemva kwi-retina ngaphakathi kweliso.

Nangona ubuchwepheshe buphucukile kwaye kukho nezinye iindlela zokulinganisa iziphene zamehlo, le ndlela ebizwa ngokuba yi-'Retinoscopy' isathandwa kakhulu kwihlabathi liphela. Phantse yinto ekufuneka yenziwe xa kusenziwa uvavanyo lwamehlo oluqhelekileyo.

Eyona nto ibalulekileyo koku kukuba ingasetyenziselwa ukuhlola amehlo abo bangakwaziyo ukunxibelelana kakuhle nokungakhululeki kwabo. Khawucinge nje, umnika njani umntwana omncinci iiglasi? Akaqondi ukuba uyakwazi ukubona oonobumba okanye akunjalo. Kwakhona, nokuba umntu ongakwaziyo ukuthetha, okhubazekileyo engqondweni, okanye onengxaki yokunxibelelana ngenxa yokwaluphala kunye nezifo zengqondo, le ndlela inokufumana inani elichanekileyo leeglasi.

Lusebenza njani olu vavanyo? Luyamangalisa!

Umgaqo osisiseko wovavanyo lwe-`Retinoscopy` ulula kakhulu. Kuxhomekeke kwindlela ukukhanya okungena ngayo elisweni lakho, kudlule kwilensi nakwi-cornea, kuze kufike kwi-`Retina` ngasemva kweliso kwaye kubonakale ngasemva.

Ukuchaneka, xa ukukhanya okukhanyayo ngokwaneleyo kukhanya ngqo esweni, umfundi ubonakala ekhanya ngenxa yokukhanya okuvela ngaphakathi kweliso. Mhlawumbi ukhe wawabona amehlo ekati ekhanya ebusuku. Yiyo loo nto kunjalo. Oogqirha bakubiza oku ngokuthi yi-fundus reflex okanye i-red reflex.

Ngokwesiqhelo, kumntu obona kakuhle, oko kukuthi, umbono we-20/20, imitha yokukhanya ebonakala kwi-retina engaphakathi kweliso kufuneka iphume kwiliso ihambelane. Kodwa ukuba unempazamo yokujika, le mitha yokukhanya igobile ngeendlela ezahlukeneyo ngenxa yaloo mpazamo. Emva koko ayiphumi ihambelane.

Kuvavanyo lwe-'Retinoscopy', ugqirha ubeka iilensi zamandla ahlukeneyo phambi kweliso lakho aze ajonge ukuba yeyiphi ilensi ebuyisela ukukhanya kwakhona elisweni. Amandla elensi oyifumanayo aba yinombolo yeresiphi yeziglasi zakho.

Olu vavanyo lunokunceda ekuxilongeni ezinye iimeko zamehlo, umzekelo:

• I-Amblyopia (iliso elivilaphayo): Ukubona kwelinye iliso kubuthathaka kunelinye.
• I-Presbyopia (ukubona izinto ezikufutshane okunxulumene nobudala): Ukungakwazi ukubona izinto ezikufutshane ngokucacileyo njengoko ukhula.
• I-Strabismus (amehlo anqamlezileyo): Ukungakwazi ukugcina omabini amehlo ejonge kwicala elinye.

Ngaba kufuneka uzilungiselele ngaphambi kovavanyo?

Ixesha elininzi, akufuneki wenze nantoni na ekhethekileyo ukulungiselela i-retinoscopy. Nangona kunjalo, kwiimeko ezingaqhelekanga, kunokufuneka wenze into ekhethekileyo. Ukuba ikhona, ugqirha wakho uya kukwazisa ngayo ngaphambi kovavanyo. Ukuba unxiba iilensi zonxibelelwano, baya kukuxelela nokuba zingaphi iiyure ngaphambi kovavanyo ekufuneka uzikhuphe.

Ngaphambi kokuba wenze i-retinoscopy eqhelekileyo, ugqirha wakho uza kubeka amathontsi akhethekileyo emehlweni akho. La abizwa ngokuba ngamayeza e-cycloplegic. La mathontsi ayawathintela amehlo akho ekugxileni ngexesha lovavanyo. Ukuba awenzi njalo, amehlo akho aya kugxila ngokuzenzekelayo, nto leyo eyenza kube nzima kugqirha ukufumana inani elifanelekileyo leeglasi zakho.

Nangona kunjalo, ukuba ugqirha uza kwenza uvavanyo olukhethekileyo olubizwa ngokuba yi-'dynamic retinoscopy', la mathontsi eliso '(cycloplegic)' awazukusetyenziswa. Kuba olo vavanyo luxhomekeke kubuchule bendalo bokugxila kwamehlo akho.

Kwenzeka ntoni ngexesha lovavanyo?

Ngexesha lovavanyo lwe-`retinoscopy`, uza kuhlala esitulweni kwigumbi elimnyama. Ugqirha uza kuhlala ejongene nawe. Isixhobo esiphambili esisetyenziselwa oku yi-`retinoscope`. Esi sisixhobo esiphathwa ngesandla esifana nethotshi encinci enelensi enkulu eqhotyoshelweyo. Ukukhanya kunye nelensi yokujonga zenzelwe ukuba ugqirha akwazi ukukhanyisa iliso lakho ngaxeshanye aze alijonge ngokusondeleyo.

Okulandelayo, kufuneka usebenzise iilensi zamandla ahlukeneyo ukuze ubone indlela ukukhanya okuvela ngaphakathi kweliso okutshintsha ngayo. Kukho iindlela ezimbini eziphambili zokwenza oku:

• I-'Phoropter': Lo ngumatshini omkhulu omile njengebhabhathane onemingxuma emibini emehlweni akho. Ukuba wakha wahlolwa amehlo, mhlawumbi ukubonile oku. Ngokutshintsha iilensi ezahlukeneyo kunye nezicwangciso ezikuwo, ugqirha unokujonga ngokukhawuleza amanani ahlukeneyo.
• Iilensi eziphathwayo:Ezi zinokuza ngendlela "yekhadi lelensi," oko kuthetha ukuba inani leelensi ezinamandla ahlukeneyo zifakelwe kwikhadi elithe tyaba. Okanye, iilensi nganye nganye zinganxitywa nganye nganye phambi kweliso (iilensi ezikhululekileyo).

Xa ugqirha ekhanyisa iliso lakho ngezi lensi, uya kuqwalasela utshintsho oluninzi ekukhanyeni kokukhanya ngaphakathi kweliso.

Ngale ndlela, ugqirha uhambisa isibane phezulu, ezantsi, ekhohlo, ekunene, nangokwe-diagonal amaxesha amaninzi. Okwangoku, utshintsha iilensi ezahlukeneyo. Angenza le nkqubo amaxesha amaninzi, eme phakathi, etshintsha isibane kwi-'retinoscope', aze abhale amanqaku encwadini. Zonke ezi zizinto eziqhelekileyo zovavanyo.

Indlela ekhethekileyo ebizwa ngokuba yi-'Dynamic Retinoscopy'

Le yenye indlela ekhethekileyo yovavanyo lwe-'Retinoscopy'. Oku kujonga ikakhulu amandla amehlo akho 'okugxila' kwizinto ezikufutshane nawe. Oogqirha bakubiza oku ngokuthi 'indawo yokuhlala'.

Ngexesha lovavanyo lwe-'dynamic retinoscopy', awufaki amaconsi emehlweni akho njengoko sele utshilo. Endaweni yoko, ugqirha wakho ukucela ukuba ujonge izinto ezikumgama owahlukileyo. Ezinye izinto zinokuba phakathi kwakho nogqirha, kwaye ezinye zinokuba ngasemva kogqirha. Ngelixa ujonge ezi zinto, ugqirha wakho ujonga amehlo akho nge-'retinoscope'. Emva koko, ngokujonga indlela ukukhanya okuhamba ngayo ngaphakathi kweliso lakho, unokufumanisa ukuba amandla amehlo akho okugxila (avumelane) asebenza ngokufanelekileyo na.

Kwenzeka ntoni emva kovavanyo?

Ukuba unikwe amaconsi eliso e-cycloplegic kuvavanyo lwakho, abafundi bakho baya kwanda okwethutyana emva kovavanyo. Oku kuthetha ukuba amehlo akho aya kwanda kancinci. Ixesha elithathayo ukuba iziphumo zala maconsi ziphele liyahluka kumntu nomntu. Ugqirha wakho uya kukuxelela ukuba kudla ngokuthatha ixesha elingakanani.

Kwakhona, unganikwa ukhuseleko lwexeshana, njengeeglasi zelanga, onokuthi uzinxibe xa uphuma. Kuba la mathontsi amehlo athintela amabala amnyama ukuba angakhuli aze anciphe ngokwawo. Oku kuthetha ukuba awakwazi ukunciphisa ukukhanya okungena emehlweni akho xa ukwindawo ekhanyayo. Ngenxa yoko, amehlo akho anokuziva ngathi ayatsha.

Ngaba kukho naziphi na iingozi ngolu vavanyo?

Enyanisweni, uvavanyo lwe-`Retinoscopy` luvavanyo olukhuselekileyo kakhulu olungenazo iingozi okanye iziphumo ebezingalindelekanga .

La mathontsi eliso akhankanyiweyo apha ngasentla anokubangela iziphumo ebezingalindelekanga ezincinci, kodwa adla ngokuba mandundu. Kwakhona, ezinye iindawo zovavanyo zinokuba nzima kumntu ovakalelwa kukukhanya okuqaqambileyo (photophobia). Ukuba unesifo sokukhanya, xelela ugqirha wakho ngaphambi kovavanyo. Ukuba unemibuzo malunga neziphumo ebezingalindelekanga zamathontsi eliso, ungabuza ugqirha wakho ngazo.

Zithini iziphumo endiza kuzifumana? Ndenza ntoni emva koko?

Emva kokuba ugqirha egqibile i-retinoscopy, uza kubala amayeza akho (okanye omthandayo) okubona. Eli nani lifana nenani olifumanayo ngokubuza imibuzo. Ugqirha uza kuchaza ukuba eli nani lithetha ukuthini, kwaye likuchaphazela njani.

Ukuba iziphumo ziqinisekisa ukuba awunawo umbono we-20/20, kuza kwenzeka ntoni emva koko?

Ukuba kunjalo, ugqirha wakho uza kuthetha nawe ngeendlela ezilungileyo zokulungisa umbono. Ezona ndlela zixhaphakileyo ziiglasi okanye iilensi zokunxibelelana . Abanye abantu banokwenza utyando lokulungisa umbono olufana neLASIK.

Iiglasi ezilungileyo zifana nesuti eyenzelwe wena. Ingcali yamehlo eyenza i-retinoscopy ifana nomthungi onobuchule, othunga ngesandla umthungo ngamnye ude ulingane kakuhle. Le ndlela ineminyaka engaphezu kwe-150 ubudala, kodwa isasetyenziswa kwiimvavanyo zamehlo eziqhelekileyo nanamhlanje. Ngoko ke, ukuba wena okanye umntu omthandayo wenza olu vavanyo, ungaqiniseka ukuba ugqirha wakho uya kukufumana ezona glasi zilungele wena.