I-chart ye-Snellen yamehlo yetshathi yokuhlola iliso esetyenziswe ngabaqeqeshi bamehlo ukujonga ubungqina obubonakalayo, okanye ukuba isiguli singabona njani ngaphandle kokuncediswa. UDkt. Hermann Snellen uphuphe isicatshulwa kwamehlo ngo-1862.
Konke malunga neTyakatheni Yamehlo ka-Snellen
I-chart ye-Snellen yamehlo yinto eqhelekileyo, isicatshulwa yamagama amakhulu kunye namancinci. Ireyiti liqukethe imizila eyi-11 yeencwadi zebhloko, ngokuqala ngoluhlu olulodwa oluphezulu kumqolo ophezulu.
Inani leencwadi kumgca ngamnye linyuka ukusuka phezulu ukuya phezulu. Ubungakanani beeleta behla ngokunyuka, ukuvumela ukuba ezinye iileta kumgca ngamnye olandelayo. Isalathisi sesiso seStellen sisebenzisa kuphela iileta ezilandelayo: C, D, E, F, L, O, P, T, kunye neZ.
Uvavanyo lweVuity Acuity
Xa uvavanya ubunzima obubonakalayo, isigulane sigubungela iso elilodwa kwaye lifunde ngokuvakalayo iileta kwitektshi, ukuqala phezulu kunye nokunyuka ukuya ngasezantsi. Umqolo omncinci weencwadi ezifunyanwa ngumguli ngokuchanekileyo unquma ubunzima obubonakalayo kwiso elingafumanwanga. Uvavanyo luphindwaphindwa ngenye iliso, kwaye ngoko kunye kunye amehlo. Ngamanye amaxesha ubonakaliso obubonakalayo buboniswa ngo- 20/20, okanye inombolo efanayo, esithetha iincwadi ezincinci zifunde ngokuchanekileyo kwitshati.
Iziphumo
Iziphumo zovavanyo lwakho lwezakhono (uvavanyo lwetshathi) ziya kugqiba umgangatho wamehlo akho. Iziphumo zakho zembono (ubuninzi) ziya kubonakaliswa njengeqhekeza.
Iziqendu ziboniswa ngakwesobunxele kwimiqolo nganye kwaye zichonga ukuba ungabona njani. Ukuba unokufunda ngokucacileyo kumgca wesihlanu, umzekelo, umbono wakho uya kuboniswa njengombono we-20/40; ukuba unokufunda ngokucacileyo kumgca wesixhenxe, umbono wakho uya kuboniswa ngo-20/25.
Ukutolika ukufunda kwakho, cinga ngamanani ezinyaweni.
Ngokomzekelo, umntu onombono we-20/60 unokufunda kwiimitha ezingama-20 apho umntu onomxholo oqhelekileyo angafunda kwiimitha ezingama-60. Amagumbi eemviwo zanamhlanje zixhotyiswe ngeteknoloji zokufunda kwesojoni, okwenza kube lula ukuvelisa ukufunda ngokuchanekileyo.
Oko Okufanele Uyazi
Kukho iinguqulelo ezininzi kule tstshana kubantu, njengabantwana abancinci, abangakwazi ukufunda iileta ze-alfabhethi. Ezinye zala macatshulwa akhethekileyo zineenkcukacha ukuchonga endaweni yeebhafabhethi okanye iinombolo. EUnited States, amanqaku angama-20/40 okanye angcono ukuba aqhube imoto ngaphandle kokusebenzisa iilensi zokulungisa. Umbono wokwesaba ngo-20/200 (okanye umbi kakhulu) uqikelela ukuba umntu uyimfama .
I-chart ye-Snellen yamehlo ingatholakala kwaye isetyenziswe kwi-intanethi ekunqumeni umgangatho wakho wombono.
Qaphela, nangona kunjalo, kuba kunokuba nzima ukufumana iziphumo ezichanekileyo kunye nezilwanyana ezahlukeneyo kunye nezisombululo ezikhoyo. Indlela efanelekileyo yokufumana ubungqina bakho bokwenene obubonakalayo kukuba novavanyo lwamehlo olwenziwa ngumqeqeshi.