Muva nje, kwakucatshangwa ukuthi ezilwaneni ijwabu leso elikhanyayo (okuthiwa wesithathu) liyilungu le-vestigial elingenzi umsebenzi. Kodwa izifundo zamuva emkhakheni wezokwelapha zezilwane (amakati ikakhulukazi) ziye zafakazela ukuthi ijwabu leso elikhanyayo liyadingeka ukuze kugcinwe amehlo ebusweni obuhle. Ijwabu leso, lapho likhanyisa ebusweni be-eyeball, lisusa izinhlayiya zothuli kulo, lihambisa i-teardrop ngokulinganayo phezu kwayo yonke indawo futhi ivikela i-cornea ekudleni. Ngakho-ke, noma yikuphi ukuvuvukala kwangaphakathi (amagama afanayo - ikhulu elikhanyayo, lesithathu) ekati lingabangela izinkinga ezinkulu nombono.
Ukwelashwa kwekhulu lesithathu kwamakati
Uma ikati linamajwabu angamashumi amathathu (kulungile nakakhulu ukuthi kukhona ukuvuvukala noma ukulahlekelwa okusobala), okokuqala, imbangela yalesi simo kufanele isungulwe. Futhi izizathu zokuphambuka kokusebenza okujwayelekile kwekhulu lesithathu kwamakati zingase zihluke kakhulu. Isizathu esivame kakhulu sokunyamalala kwejwabu leso elibonakalayo likhona emehlweni e-stimulus (isibonelo, ukungena komzimba wangaphandle) noma ukuphulwa kwe-cornea iso. Ngokuvamile ukuvuvukala kwejwabu leso lesithathu kumakati kubonakala ezifweni zamehlo, isibonelo, nge- conjunctivitis . Ukuthinta isimo sejwabu leso langaphakathi nesifo se-etiology ye-viral kanye nenye isifo emsebenzini wezinambuzane zomzimba. Kodwa, noma kunjalo, ukuphatha noma yikuphi ukuguqulwa ngekhulu lesithathu emakathini , futhi ngisho nangaphezulu uma lesi sifo sihambisana nokulahlekelwa yidla, isifo sohudo, umkhuhlane, kufanele uhambe emtholampilo wezilwane. Udokotela wezilwane kuphela, lapho ehlaziye zonke izimpawu, angachaza inkambo yokwelashwa okudingekayo. Ngendlela, imbangela yokulahlekelwa kwekhulu lesithathu, engadingi ukungenelela kwezokwelapha, kungase kube ukwedlulela ngokweqile kwesilwane (isibonelo, ngokuzama kwemizamo). Ngokuvamile, uma impilo yenkathi ngokuvamile ingabangeli ukukhathazeka, isimo sejwabu leso elingaphakathi kulesi simo sivamile ngaphandle kokungenelela kwezokwelapha.