Thaum koj nyob hauv tsev kawm ntawv qib siab, tej zaum koj yuav tau kawm tias Benjamin Franklin tau tsim "bifocals" thiab xav tias txhais tau tias "iav iav." Thaum Franklin tau ua tiag tiag tsim bifocals hauv 1779, nws tsis tau tsim tsom iav rau lawv tus kheej - nws tsuas yog tsim ib qho qauv nrog ntau lub lo ntsiab muag uas tuaj yeem pab tib neeg nrog ntau dua …
Leej twg tsim cov bifocals?
Benjamin Franklin, leej twg tuag 200 xyoo dhau los, feem ntau suav nrog kev tsim khoom ntawm bifocals. Txawm li cas los xij, cov kws sau keeb kwm loj muaj qee lub sijhawm ua pov thawj los qhia tias lwm tus yuav tau ua ntej nws hauv qhov kev tsim.
Puas yog Franklin tsim bifocals?
Zoo li peb feem coob, Franklin pom tias nws qhov muag tsis pom kev zoo zuj zus thaum nws loj tuaj, thiab nws loj hlob ob qho tib si pom ze thiab pom deb. Nthuav ntawm kev hloov ntawm ob khub tsom iav, nws tau tsim " ob lub tsom iav, "los yog qhov peb tam sim no hu ua bifocals.
Thaum twg Ben Franklin tsim bifocals?
Bifocals, kev sib xyaw ntawm ob qho tib si concave thiab convex lo ntsiab muag rau ob hom kev kho qhov muag, lub lens sab saum toj rau kev pom nyob deb thiab lub lens qis rau kev nyeem ntawv, tau tsim ncig 1760los ntawm Tebchaws Asmeskas thiab tus neeg tsim khoom Benjamin Franklin.
Vim li cas Ben Franklin tsim cov bifocals?
Franklin los txog lub tswv yim vim nws "laus" thiab muaj teeb meem pom ob qho tib si nyob ze thiab deb. … Nws nkees ntawm kev hloov ntawm ob lub tsom iav sib txawv, yog li nws tau tsim ib txoj hauv kev kom haum ob hom lo ntsiab muag rau hauv ib lub thav duab.
