BOSIRA

BOSIRA (Visus, visio), binoi, binish, yake az uzvhoi hissi panjgona; qobiliyati darki andoza, shakl va rangi ashyo, joygiri va masofai bayni onho. CHashmi inson faqat mavjhoi nuri daroziashon muayyan – takhminan az 390 to 760 nm-ro dark mekunad. Nurhoi daroziashon kam (ultrabunafsh), yo ziyod (infrasurkh) dar inson ehsosi binishro ba vujud nameorand.
Nurhoi rushnoii chizhoi didashavanda ba vositai gavharak ba chashm guzashta, ba turpardai hissi rushnoi (shabakiya), az jumla ba hujayrahoi on – hujayrahoi makhrutshakl va qalamchashakl tasir merasonand va dar onho angezishi asabro ba vujud meorand. In angezish ba vositai asabi binoi ba markazi qishri B., ki dar magzi pushti sar (nig. Sistemai asabi markazi) voqe ast, intiqol meyobad. Dar in jo angezishi nuri dar shakli obrazhoi muayyan va taassurot dark karda meshavad.
Dar shabakiya taqriban 7 mln. hujayrai makhrutshakl va 12 mln. hujayrai qalamchashakl mavjud ast. Miqdori asosii hujayrahoi makhrutshakl dar markazi shabakiya, ki dogi zard nom dorad, joygir shudaand. Barobari az markaz dur shudan, miqdori hujayrahoi makhrutshakl kam meshavad, vale shumorai hujayrahoi qalamchashakl meafzoyad. Dar kanori shabakiya faqat hujayrahoi qalamchashakl hastand. Onho qobiliyati khele balandi hissi nurro doshta, baroi dar shomgohon yo shab didan musoidat mekunand.
Qobiliyati chashm dar bobati farq kardani tobishhoi khele ziyodi ranghoi gunogun bagoyat muhim ast. Hamai tobishhoi rangi hangomi omezish yoftani chand range az haft rangi asosii spektr – surkh, noranji, zard, sabz, kabud, nilobi va bunafsh ba vujud meoyad. Olimi rus M.V Lomonosov isbot namud, ki asosi spektro se rang – sabz, surkh va bunafsh (yo nilobi) tashkil medihad; ranghoi digarro boshad, dar natijai omezish dodani se rang hosil kardan mumkin ast. Dar hamin asos T. YUng va G. Gelmgolts takhmin namudand, ki dar shabakiya se unsur (yo tarkib) vujud dorad va har yake az on baroi beshtar dark namudani faqat yake az in rangho tain gardidaast. Dar asnoi ba chashm tasir rasonidani nurhoi rangin muvofiqan in yo on unsur angezish meyobad, ki baroi darki gunogunii tobishhoi rangho imkoniyat medihad. Nazariyai sertarkibai binishi rangho nazariyai mamul boshad ham, aqidai yagona nest (nig. Rangbini). B.-i shabona aksar vaqt hangomi dar khurok kam budani vitamini A (nig. Vitaminho, Vitaminkohish) khalal meyobad. Hujayrahoi makhrutshakl, ki ba toriki hassosiyati kam dorand, asosan B.-i ruzonaro tamin namuda, shakl, rang va juziyoti predmetro nagz farq mekunand.
Dogi zard, khususan chuqurchai markazi on, ki faqat az hujayrahoi makhrutshakl iborat ast, joi B.-i ravshan, yane B.-i markazi meboshad. Qismhoi digari shabakiya ba B. i. pahlui yo kanori musoidat menamoyand (bo on shakli predmet noravshan dark karda meshavad). B.-i markazi didani juziyoti khurdi predmetho, B.-i kanori boshad, imkoniyati dar fazo muayyan namudani mavqero tamin mesozad.
Ehsosi shabakiyai chashm ba rushnoi khele baland ast. Rushnoii sham dar shabi torik dar masofai chand kilometr dark karda meshavad. Qobiliyati balandi tagiyrpazirii in guna hassosi ba uzvi binoi imkon medihad, ki ham dar ravshani va ham dar toriki dida tavonad.
Qobiliyati muvofiq gashtani chashm ba idroki nurhoi rushnoiashon gunogun mutobiqat nom dorad. Baroi faro rasidani mutobiqati komil, odatan, chand muddat lozim ast.
Qobiliyati chashm dar bobati alohida farq kardani du nuqtai masofaashon nihoyat kam (minimali) tezii B. nom dorad. Meyori tezii B. kunje meboshad, ki nurhoi az in nuqtaho ravanda tashkil kardaand. In kunj har qadar khurd boshad, chashm hamon qadar khub mebinad. Buzurgii minimalii kunji B.-i aksar odamon ba 1 daq. barobar ast. Tezii binishi chashm, ki kunji kamtarini bosiraash 1 daq. meboshad, hamchun vohidi tezii B. qabul shudaast, vale in buzurgii miyonai norma meboshad. Tezii chashmi baze odamon az vohid kamtar va odamoni digar az vohid ziyodtar ast. Baroi muayyan kardani tezii B. jadvalhoi makhsusro istifoda mebarand, ki dar onho alomathoi ozmoishi andozaashon gunogun – harfho, halqaho, suratho sabt yoftaand. Baroi baho dodan ba B.-i kanori bo asbobhoi makhsus hududi maydoni B., yane qismi fazoero, ki bo chashmi beharakat dida meshavad, muayyan mekunand.
Hangomi bo hardu chashm didani predmet tasviri on ba nuqtahoi yakkhelai shabakiyai har du chashm meaftad va odam predmetro na juft, balki yaklukht mebinad. Agar tasviri predmet ba qitahoi yakkhelai shabakiyai har du chashm naaftad, har chiz duto menamoyad, yane holati ahvali ba vujud meoyad. B.-i mutadili yakjoya bo hardu chashm B.-i binokulyari yo stereoskopi nomida meshavad; on baroi idroki aniqu komili predmeti didashavanda va durust muayan namudani joy dar fazo musoidat mekunad.
Baroi nigoh doshtani B.-i mutadil faroham ovardani sharoiti musoidi behdosht ahamiyati kalon dorad. Az in jihat ravshanii durustu kofi baso muhim ast. Baroi bemonea ba khona aftidani ravshanii ruz shishahoi tirezaro toza nigoh doshtan lozim ast; dar zertakhtai tireza gulhoi baland guzoshtan lozim nest. Ba tirezaho baroi bartaraf namudani tasiri nurhoi rosti oftob boyad pardahoi safed ovekht. Ravshanii tabii dar khona az darajai inikosi rushnoii ruz dar saqf, devorho, mebel va dig. ashyo vobasta ast. Binobar in ashyoi inikosi rushnoi boyad bo tobishhoi safed va beshtar zardi sabztob rang karda shavand.
Baroi rushnoii suni az lampahoi lyuminestsenti istifoda burda meshavad. Rushnoii onho ba rushnoii ruz nazdik va baroi chashm guvoro meboshad. Dar khona baroi kor boyad dar nazdi tireza joi ravshan judo karda shavad. SHomgoh az lampai 40 – 60 vattai sarpushash noshaffof istifoda burdan behtar ast. Onro dar boloi miz tavre guzoshtan lozim, ki rushnoi az tarafi chap faqat ba joi kori aftad, chashm boshad, dar joi soya monad. Masofai bayni chashm va kitob (yo daftar) boyad ba hisobi miyona 30 – 35 sm boshad. On taqriban ba darozii dast az orinj to nugi angushton barobar ast. CHunin masofa chashmro khasta namesozad va baroi kham nashuda nishastan imkon medihad. Dar ravshanii khira, hangomi rohgardi va dar naqliyot khondani kitob mumkin nest. Holati noustuvori kitob yo gazeta dar vaqti harakati naqliyot khondanro dushvor megardonad, baroi ba chashm khele nazdik ovardani matn majbur mekunad va boisi khastagii chashm megardad.
Kori B.-ro bo istirohati chashm andarham kardan muhim ast. Badi har 30 – 40 daq. kor 10 daq. istirohat boyad kard. Hangomi tamoshoi barnomahoi televizion az ekran dar masofai kamash 2,5 metr dur isted. Dar ayni vaqt khona boyad ba tavri mutadil ravshan boshad.
Ba gigienai B.-i kudakon diqqati makhsus boyad dod. Bo in maqsad baroi kudakon meyorhoi kori bosiravi tartib doda shudaand. Ba nishasti durusti onho dar vaqti mashguliyat, ba ravshanii boyadu shoyadi joyi kor va rioyai qatii tartibi ruz etibor dodan zarur ast. Badi andake shikoyati kudak az khastagii chashm uro favran ba dukhturi oftalmolog nishon dihed. Nig. niz CHashm.
KL
Sokhtori guzai chashm; burrishi dar sathi amudi.
Kajii gunoguni gavharak: az chap – hangomi sust budani mushaki mijgoni; az rost – hangomi kashish yoftani mushaki mijgoni. 1 – qarniya (shokhparda); 2 – dahlezi peshi chashm; 3 – gavharak (bulurak); 4 – inabiya; 5 – dahlezi qafoi chashm; 6 – konyunktiva (multahima); 7 – mushaki rosti laterali; 8 – safedparda; 9 – ragparda (khorioidea); 10 – shabakiya; 11 – chuqurchai markazi; 12 – asabi bosira; 13 – chuqurii qurs (disk); 14 – mehvari beruni chashm; 15 – mushaki medialii rost; 15 – mehvari kundalangi guzai chashm; 16 – mehvari kundalangi guzai chashm; 17 – jismi mijgoni; 18 – tasmachai mijgoni; 19 – mehvari bosira.