I-Astigmatism

I-Astigmatism luhlobo lweempazamo ezibonisa ukungaboni ngamehlo. Iimpazamo ezibonakalisayo zibangela umbono ophuthileyo. Zezona zizathu zixhaphakileyo zokuba kutheni umntu esiya kubona ingcali yamehlo.

Ezinye iintlobo zeempazamo ezibonakalisayo zezi:

• Ukubona kude
• Ukubona ngaphambili

Abantu bayakwazi ukubona kuba indawo engaphambili yamehlo (i-cornea) iyakwazi ukugoba (ukukhanyisa) ukukhanya kwaye ijolise kwi-retina. Lo ngumphandle wangaphakathi wamehlo.

Ukuba imitha yokukhanya ayigxilanga ngokucacileyo kwi-retina, imifanekiso oyibonayo isenokuba mfiliba.

Nge-astigmatism, i-cornea igobile ngokungaqhelekanga. Le curve ibangela ukuba umbono ungabikho ekugxilwe kuwo.

Unobangela we-astigmatism awaziwa. Idla ngokubakho kwasekuzalweni. I-Astigmatism ihlala yenzeka kunye nokubona kwangaphambili okanye ukubona kude. Ukuba i-astigmatism iya isiba mandundu, inokuba luphawu lwekeratoconus.

I-Astigmatism ixhaphake kakhulu. Ngamanye amaxesha kwenzeka emva kweentlobo ezithile zotyando lwamehlo, ezinje ngokuhlinzwa ngamehlo.

I-Astigmatism yenza kube nzima ukubona iinkcukacha ezintle, nokuba zikufutshane okanye zikude.

I-Astigmatism ichaphazeleka ngokulula kuvavanyo lwamehlo oluqhelekileyo kunye novavanyo lokujonga kwakhona. Iimvavanyo ezizodwa azifuneki kwiimeko ezininzi.

Abantwana okanye abantu abadala abangakwaziyo ukuphendula kuvavanyo oluqhelekileyo lokuphinda bakhuphe banokuphinda bakalwe ngokuvavanywa kusetyenziswa ukukhanya okubonisiweyo (i-retinoscopy).

Ubuncinci be-astigmatism kusenokungafuneki ukuba bulungiswe.

Iiglasi okanye iilensi zonxibelelwano ziya kulungisa i-astigmatism, kodwa ungayinyangi.

Utyando lwe-Laser lunokunceda ukutshintsha ubume bomphezulu we-cornea ukuze kupheliswe i-astigmatism, kunye nokubona kwangaphambili okanye ukubona kude.

I-Astigmatism inokutshintsha ngokuhamba kwexesha, ifuna iiglasi ezintsha okanye iilensi zonxibelelwano. Ukulungiswa kwembono ye-Laser kunokuthi rhoqo kuphelise, okanye kunciphise kakhulu i-astigmatism.

Kubantwana, i-astigmatism engachanekanga kwiliso elinye inokubangela i-amblyopia.

Fowunela umboneleli wakho wezempilo okanye ugqirha wamehlo ukuba iingxaki zombono ziya zisiba mbi, okanye ungaphuculi ngeiglasi okanye iilensi zonxibelelwano.

• Uvavanyo lwe-acuity ebonakalayo

UChiu B, uJA omncinci. Ukulungiswa kweempazamo ezichasayo. Ku: Yanoff M, Duker JS, ii-eds. Ophthalmology. Umhla we-5. IPhiladelphia, PA: Elsevier; I-2019: isahluko 2.4.

UJain S, Hardten DR, Ang LPK, Azar DT. I-excimer laser surface ablation: i-keratectomy yefotoreptomy (PRK), i-laser subepithelial Keratomileusis (LASEK), kunye ne-Epi-LASIK. Ku: Yanoff M, Duker JS, ii-eds. Ophthalmology. Umhla we-5. IPhiladelphia, PA: Elsevier; I-2019: isahluko 3.3.

U-Olitsky SE, uMarsh JD. Ukungaqhelekanga kokukhutshwa kunye nendawo yokuhlala. Ku: Kliegman RM, St Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, ii-eds. Incwadi kaNelson yeNcwadi yePediatrics. Umhla wama-21. IPhiladelphia, PA: Elsevier; 2020: isahluko 638.