Lub hauv paus ntawm qhov muag yog dab tsi?
Lub hauv paus ntawm qhov muag yog dab tsi?

Video: Lub hauv paus ntawm qhov muag yog dab tsi?

Video: Lub hauv paus ntawm qhov muag yog dab tsi?
Video: Qhov Ntawm Ko Yog Dab Tsi 2024, Cuaj hlis
Anonim

Feem ntau, lub teeb tau tsom mus rau qhov retina ntawm qhov chaw hu ua focal taw tes . Ib tus neeg tsis pom kev qhov muag yog ntev dua ntawm pem hauv ntej mus rau sab dua li ib txwm qhov muag ua rau lub teeb tsom mus rau pem hauv ntej ntawm lub qhov muag es tsis txhob ncaj qha mus rau nws.

Qhov ntawd, dab tsi yog qhov ntev focal hauv qhov muag?

Tsuas yog tom qab lub iris thiab menyuam kawm ntawv yog lub lens. Lub lens yoog kom hloov pauv nws txoj kev nkhaus thiab ua kom tiav cov txheej txheem. Thaum ib yam khoom nyob ntawm infinity, tus focal ntev , los yog nrug deb los ntawm lub cornea mus rau retina, ntawm ib txwm so qhov muag yog li 1.7 cm (17 mm).

Tsis tas li, lub zog ntawm lub qhov muag zoo li cas? Hauv tib neeg, tag nrho kev kho qhov muag hwj chim ntawm kev so qhov muag yog kwv yees li 60 dioptres. Lub qhov muag nyiaj rau kwv yees li ob feem peb ntawm qhov cuam tshuam no hwj chim (kwv yees li 40 dioptres) thiab lub lens crystalline pab txhawb ib feem peb (txog 20 dioptres).

Yog li ntawd, vim li cas lub hauv paus ntsiab lus tseem ceeb hauv kev pom?

Cov Tseem ceeb ntawm a Focal Point . A focal taw tes yog ib feem ntawm cov duab uas kos rau qhov muag ntawm tus saib rau feem ntau tseem ceeb ib feem ntawm daim duab lossis thaj chaw uas koj xav ua kom pom tseeb. Nws frustrates lub qhov muag ntawm tus saib yog tias tsis muaj focal taw tes , as ua qhov muag tsis yog kos rau ib qho tshwj xeeb ntawm daim duab.

Yam tsawg kawg focal ntev ntawm qhov muag ib txwm yog dab tsi?

Cov focal ntev ntawm qhov nruab nrab , noj qab nyob zoo, neeg laus qhov muag ntawm qhov ze-taw tes yog li 18.5 hli. Cov neeg hluas tuaj yeem ua raws lawv lub iav ntxiv rau a focal ntev ntawm ib ncig 15.4 mm.

Pom zoo: