Table Sivtseva - mafi kyau mataimakin a cikin ganewar asali na mutum hangen nesa

Human wahayi - daya daga cikin manyan kuma a lokaci guda m damar iya yin komai. Baya shi ne zama dole duk lokacin da za a duba. Kari zuwa ophthalmologist ya zama lokaci-lokaci aikin yi a rayuwa na kowane mutum.

Duba view a zamani ophthalmology

Back a cikin Tarayyar Soviet masana kimiyya Sivtsev da aka kirkiro da wani makawa ga kayan aiki na zamani ophthalmology, wanda yake a cikin marubucin daraja da ake kira "tebur Sivtseva". Amfani da wannan hanya domin kayyade na gani acuity. Domin wannan jerin 12 ãyõyi aka gano: da haruffa da zobba da rata, wanda, fara daga saman jere zuwa kasa hankali rage. Daga nesa na 5 mita gani acuity aka ƙaddara a kan sikelin daga 0.1 zuwa 2.0.

Mene ne na gani acuity da kuma yadda aka tabbatar da Sivtseva tebur?

Kayayyakin acuity - da ikon da mutum ido rarrabe tsakanin biyu da maki da suke baya da wani nesa. Yanzu dokokin ce cewa ido da ciwon 100% wahayi iya bambanta da maki biyu, spaced baya an kusurwa nesa na minti daya. Saboda haka, na gani acuity za a iya bayyana a matsayin ikon gani a sarari da kuma bayyana irin taka tsantsan ido dijital nuna alama 100% ko 1.0. Sivtseva tebur kawai tsara a cikin irin wannan hanya da cewa dijital nuna alama kuma ƙayyade.

Akwai yanayi inda idon mutum ne haka da raya cewa, yana yiwuwa ya kimanta da sharpness na 1.2 ko 1.5 ko 3.0. Duk da yake da ido a cututtuka daban-daban, kamar yadda nearsightedness ko farsightedness, astigmatism ko glaucoma, mahaukaci iya zama 0.5 ko 0.05.

Sau da yawa bayyana na gani acuity amfani percentages. Duk da haka, ya kamata a lura da cewa kawai 100% adadi yayi dace da 100% na gani gani. Alal misali, a gani nuna alama a 0.2 diopters ba za a iya fassara zuwa wani kaso daga 20% a matsayin gani. Wannan adadi yayi dace da 49% na kullum. Ba haka sauki fassara kowane Figures zuwa percentages da kuma mayar. Kuma musamman wannan tebur Sivtseva - girma a cikin ginshikan a kan hagu da kuma dama an riga lasafta sakamakon gwajin.

Yadda za a duba na gani acuity Sivtseva tebur?

A misali sa na buga haruffa na daban-daban masu girma dabam gina a cikin 12 jerin. Duk da haruffa na Rasha haruffa - W, B, M, H, K, N. Kowane ƙananan jere - haruffa karami fiye da saman. Cak dole ne a da za'ayi a cikin wani dakin da kyau lighting. An bayar da wani musamman fitila, da nufin a tebur da kuma ciwon diffused haske. A nesa na 5 mita daga tebur view aka bari Sivtseva. A haƙuri kamata zauna kage da kuma, alternately rufe hagu da kuma dama da idanu, karanta harafi daga tebur. Idan bari saukin kira haruffa har zuwa 10 layuka, la'akari da cewa yana da 100% gannai. Idan shi yana tsayawa a wasu daga cikin cirewa jerin, na gani acuity ne m da sigogi a dama shafi na tebur.

A haƙuri iya zama kusa fiye da 5 mita daga tebur, amma a cikin wannan hali na musamman dabara da ake amfani da sanin da tsananin:

V = d / D

V a cikin wannan lissafi - da darajar da muke da ƙayyade, wato, na gani acuity. d - da nesa a da haƙuri ne a kan tebur. D - da nesa a da haƙuri bambanta wani yawan haruffa.

Yanzu, da cikakken bayani game da yadda za tebur ya kamata a sanya Sivtseva. An sanya tsakanin biyu mai kyalli fitilu haka cewa haske ya kai 700 lumens. Ƙananan gefen tebur ya kamata a wata tsawo na 120 cm daga bene. A haƙuri zaune kage, rike kansa kafa, eyelids na biyu idanu bude a cikin al'ada matsayi. A daya ido a haɗe musamman fari farantin. A cikin 3 da dakika verifiable show da wasika cewa ya kamata a kira. A wannan yanayin, fara daga ƙananan kuma sannu a hankali tashi zuwa fi girma ãyõyi. Idan dukan alamu an kira - yi bari 100% ko 1.0 hangen nesa. Idan daya ko fiye haruffa ba su gane - bai cika na gani acuity. Don sanin da na gani acuity kasa da 0.1 haƙuri hankali kusanci tebur kowane 0.5 m, yayin da shi ba zai iya sanin ko alamun tebur.

Legend zuwa Table Sivtseva

Bugu da kari ga haruffa na Rasha haruffa za a iya gani cewa akwai biyu ginshikan, wanda aka sanya da Latin haruffa D kuma V. A lambobi a cikin D-shafi nuna nesa kasancewa a kan tebur daga wanda wani mutum ne wanda na gani acuity ne daidai to 100%, za a iya sauƙi karanta daga hagu tsaye alama. Lambobi a cikin V-shafi - mai lamba halayyar acuity, idan wannan adadin da aka karanta aka bari a kan 5 mita nesa.

Abin da sauran allunan amfani a ophthalmology?

Tun da hangen nesa ne mai matukar muhimmanci mutum ikon da za a kiyaye a cikin mai kyau yanayin, akwai da dama daga gwaje-gwaje a yi amfani da ophthalmology, wanda ba ka damar nuna hakikanin hoto na jihar da ido.

• Duba gani acuity - Sivtseva tebur (as shi ne ake kira a wasu kafofin) an halitta don wannan manufa. Yana amfani da harafin W, D, F, H, K, N. Orlova kuma yi amfani da wani tebur yara, inda haruffa ake amfani maimakon images (da alama, wani naman gwari, a doki, wani sintali, wani jirgin saman, duck, giwa, inji, herringbone).
• bambanci wahayi gwajin - domin wannan tebur Golovin an halitta. Yana amfani 4 iri optotypes - zobba da hutu a daya daga cikin 4 bangarorin
• Duba myopia da hyperopia - amfani da duohromny gwajin kunshi biyu halves na wani bango na launi daban-daban: ja da kore, da wannan bango, shirya da haruffa (A, H, W, F, I, B, S). A sakamakon gwajin, shi ne niyya ko al'ada gani (ido ganin haruffa a duka backgrounds m). Idan haruffa a kan wani ja bango guda jere bayarda fiye da a kan kore, akwai wani myopia, a kan m - sightedness.
• Duba for astigmatism - ya fi na kowa gwajin da ake kira da Siemens Star. Jigon da gwajin ne cewa wani mutum da al'ada wahayi gani a kan layi a kasa cewa, kafin kai da cibiyar, fara blur da zoba juna. A tsakiyar line sake zama a fili bayyane.