Vanachiremba vemaziso vanogara vachikanda kumativi ose izwi rokuti "20/20" chaizvo. Kazhinji nguva, pasina kufunga, vanachiremba vemaziso uye vanogadzira maziso vanoshandisa izwi 20/20 vasina kudzidzisa varwere vavo pamusoro pezvazvinoreva chaizvoizvo. "Mr. Smith, iwe une maonero 20/20 ... haisi iyo inonakidza here? "Vakawanda vasvika pakunzwisisa kuti kuva nemaonero 20/20 kwakakwana, zvakasikwa kana zvimwe chinhu chakanaka.
Nguva dzose tarisa purogiramu yemashoko, 20/20? Iro zita rakanaka rekuratidzwa kwemashoko inova nechinangwa chekujekesa kana kuonekwa kwakanyatsojeka pane dzimwe nhau dzakanaka.
Kuyera Chiratidzo
Kuonekwa kwevanhu kwakaoma. Nemaonero edu ane maitiro akawanda asi vashandi vekuchengeta maziso vanoda imwe nzira yekuenzanisa kana kuyera maonero. Kana tikakwanisa kuenzanisa maonero, tinogona kutaurira kuti kure kure nekureruka kunogona kuva kana kuti kururamisa kunofanirwa kurongerwa sei kuunza munhu chaiye kune zvatinofunga sechinhu chinowanzoonekwa. Zvingava zvakaoma kududzira maonero kana tangoti, "Maonero ari pedyo nekusingaperi" kana "Chiratidzo chinoratidzika zvakanaka." Icho hachisi iyo nzira yepamhizha yekunyora kuongorora kwedu. Zvingava zvakajeka zvakanyanya kunyora chiratidzo cheumwe munhu sa 20/30. Nenzira iyi, tinokwanisa kutarisa pane imwe nguva yenguva iyo maonero edu angaita sei kana kuti haagoni kuchinja.
Snellen System of Visual Acuity
Kune kushamiswa kwevanhu vakawanda, kuongorora kweziso kwaro kwakanyanya kwakaoma.
Nokuti ziso rako uye maonero ako chikamu uropi hwako uye nervous system, kune zvinhu zvakawanda pane chiremba chekuongorora chekutsvaga. Yokutanga uye zvichida kuyerwa kunonyanya kukosha ndechekuona kwepakati, kana pakati pemaonero anooneka. Ichi chikamu chechiono chedu chatinoshandisa patinenge tichigadzirisa ziso redu pane chimwe chinhu kuti tione.
MuUnited States, tinoshandisa Snellen system yekuona acuity. Nhamba yepamusoro, 20, inoreva kurema kwekuyera kumakumbo mumakumbo. Masayendisiti akasarudza pamakumbo makumi maviri nokuti chinhu chipi nechipi chatinenge tichiona icho chakareba mamita makumi maviri kana kupfuura chinotaridzwa optical infinity. Vakasvika pamhedziso iyoyo nekuda kwenzira iyo mafungu anofamba uye nzira iyo meso edu anotarisa zvinhu. Mune ziso rinowanzoonekwa, rakakwana, rinotarisa munhu, musungo unotarisa uri mukunyatsosununguka zvachose paunoona zvinhu zviri pamamita makumi maviri kana kupfuura. Kana zvinhu zvichitanga kuswedera pedyo nemeso edu kupfuura mamita makumi maviri, ziso redu rinotanga kuchinja chinangwa chavo kuitira kuti chichengetedze zvakajeka.
Uyezve, chirongwa cheSnellen chinotora kuti ziso rinowanzova rakanaka kana rikwanisa kugadzirisa zvimwe tsanangudzo mumakiromita makumi maviri. Izvo zvinyorwa zvinotsanangurwa senzvimbo iyo imwe neimwe yechinyorwa, somuenzaniso, tsamba E, inenge yakakwirira yepamusoro yeminiti imwe yeArc. Imwe miniti ye arc yakaenzana ne1 / 60 ye degree. Tsamba yose inoita maminitsi mashanu eArc. Kuti unzwisise izvi, unofanirwa kudzokera kune geometry uye kudhonza kunze kwekona katatu uye kuenzanisa chikamu chekatatu. Mugumo mukuru wekona katatu ndiyo tsamba E, ine zvikamu zvishanu ... nzvimbo yepamusoro yeE, nzvimbo, bhatikati, nzvimbo uye pasi reziso.
Nzvimbo yacho ndeyemaminitsi mashanu eArc yetsamba yose neminiti imwe yeArc kubha imwe neimwe.
Saka Ko 20/400 Inorevei?
Nokuda kwemuenzaniso, nhamba yepasi muzwi rokuti 20/400 ibanga apo tsanangudzo yebhuku imwe neimwe inoshandisa miniti imwe yeArc. Saka, kana munhu akamira mamita mazana mana kubva kuE E pa chati yemaziso, chimwe nechimwe cheE chinoshandisa miniti imwe yeArc. Izvi zvakava chiyero nokuti meso evanhu uye maitiro ehutano muuropi anotibvumira kusarudza nyore nyore pakati pemakumbo ane zvinhu zvinoshandisa imwe miniti yeArc.
Imwe nzira yekufunga pamusoro peizvi ndeyokuti kana mumwe munhu akayerwa kuva nemakore 20/50, munhu iyeye anofanira kutamira kusvika mamita makumi maviri kuti agone kugadzirisa tsanangudzo shomanana mumutsamba, asi shamwari yavo yakakwana inogona kumira nenzira yakadzoka pamakumbo makumi mashanu uye kugadzirisa tsanangudzo shomanana.
Kushandisa Mirrors muZvinyorwa Zvokuongorora
Kana iwe uchifunga nezvazvo, dzakawanda dzemakamuri ekuongorora optometrists anoshandisa haisi mamita makumi maviri pakureba. Zvinofadza kuti kungoisa girazi kunomiririra kureba kwemarefu makumbo makumi maviri. Kana kamuri yakareba mamita gumi, kuisa girazi kuti igadzire chati chemaziso inoita kuti nzvimbo ioneke mamita makumi maviri kusvika kumeso. Nyanzvi dzekuongorora dzakagadzirisa zvakanakisisa pakuchengeta marati emaso maererano nechepakati kure kubva kune zverwere kusvika pagirazi uye kubva kubva pagirazi kuenda kunejeri chekuona maziso. Nekuuya kwemashiripiti emaziso, kuvharidzirwa kuri nyore.
Ima 20/20 Ndeyechokwadi Here?
Tinofanira kutora maonero 20/20 kuti avereji wekuonekwa kwemazuva ose. Zvisinei, sekuwanda kwezviyero muhutano hwehutano, kune "yakakwana" yezvakaratidzwa. Vamwe vedu vanogona kuona zvishoma pasi pe20/20, vanoti 20/25, uye vamwe vedu vanogona kuona zviri nani kudarika 20/20, vanoti 20/15, uye vachiri kuonekwa sechinhu chakanaka. Mamwe mapepa emeso anogadzirirwa kujekesa kukura kwemashoko kusvika kure pasi se20/10, sezvo zvisiri nyore kuwana munhu anoona zviri nani kudarika 20/10. Kugadzirisa kwepfungwa yedu yepakati yakafanana nekombiyuta yakagadziriswa yakawanda. Kana iyo pixels yakanyatsonaka uye yavharana pamwe chete, kugadzirisa kwekuongorora kwakanaka. Vhidhiyo veTV vanoongorora maonero ekuona . Ikoko inosvika pane imwe nzvimbo apo imwe sarudzo yeTV yakareba kupfuura yakanakisisa yevanhu inoonekwa acuity haizoiti mutsauko. Kana kusarudzwa kweTV kuri nani kudarika izvo ziso revanhu rinogona kugadzirisa, chii ichocho?
SOURCE: Kliniki inogadziriswa mumagetsi, Eskridge, J, Amos, J., Bartlett, J., JB Lippincott Company, 1991.