I-Myopia dan ukubona eduze kungenziwa kube okujwayelekile kusetshenziswa amalensi ezibuko zamehlo dan amalensi okuxhumanaAmalensi ezibuko zamehlo anamathele ezibukweni zamehlo, kuyilapho amalensi okuxhumana enamathele kumfundi weso. Izibuko zikude kakhulu neso, kuyilapho amalensi okuxhumana enamathele esweni, ngakho-ke ibanga eliphakathi kwelensi yokuxhumana neso alinakwa.
Lesi sihloko sichaza izibonelo zezinkinga ezibhekene nabantu ababona eduze nababona kude, izinhlobo zamalensi asetshenziswa ukulungisa umbono, kanye nobude obuqondile namandla ala malensi. Lesi sihloko sigxile ekusetshenzisweni kwe i-kacamata ekwenzeni amehlo aqonde eduze namehlo aqonde kude abe ngcono.
Ukubona Okuseduze Namalensi Agobile
Iphuzu elikude iso elibona eduze noma i-myopia lingama-102 cm. Ukuze iso elibona eduze libone izinto ngokucacile ngokungapheli, nquma (a) uhlobo lwelensi esetshenzisiwe, (b) ubude be-focal lens, (c) amandla noma amandla elensi.
Amalensi ezibuko ngokuvamile aqhele ngamasentimitha amabili ukusuka emehlweni.
Ingxoxo
(A) Uhlobo lwelensi esetshenzisiwe
Ngesihloko ukubona eduze Kuye kwachazwa ukuthi amalensi asetshenziselwa ukulungisa amehlo aseduze angamalensi agobile noma amalensi ahlukene noma amalensi angemihle.
(B) Ubude bokugxila kwelensi
Ukuze into ebonwa yiso elibona eduze ngelensi yezibuko ibe kude kakhulu, ilensi kumele yakhe isithombe ebangeni elingamasentimitha ayi-102 phambi kweso, okuyiphuzu elikude leso elibona eduze. Ilensi yezibuko ingamasentimitha ama-2 ukusuka esweni ngakho isithombe singamasentimitha ayi-100 phambi kwelensi. Isithombe siphambi kwelensi, ngakho-ke isithombe sibonakala futhi siqondile (qhathanisa incazelo esihlokweni isithombe selensi egobile)
I-Diketahui :
Ibanga lezinto = okungapheli
Ibanga lesithombe (s') = -100 cm (elibi ngoba isithombe sibonakala ngeso lengqondo)
Kubuziwe Ubude (f)
Jawab :
1/f = 1/s + 1/s'
1/f = 1/~ + (- 1/100)
1/f = 0 – 1/100
1/f = – 1/100
f = – 100/1 cm = -100 cm = -1 imitha.
Ubude obuqondile obungalungile busho ukuthi ilensi esetshenzisiwe iyasebenza. ilensi egobile noma ilensi ehlukahlukene.
(C) Amandla ngelensi
P = 1/f = 1/-1 m = -1 ama-Diopters
Amandla noma amandla elensi angu--1 D. Uphawu olubi lusho ukuthi ilensi esetshenziswayo ilensi egobile noma ilensi ehlukanayo.
Ukubona Okuseduze Namalensi Aqondile
Iphuzu eliseduze leso lomuntu obona eduze lingu-102 cm. Ukuze umuntu akwazi ukufunda ebangeni elingama-25 cm phambi kweso, nquma (a) uhlobo lwelensi esetshenzisiwe, (b) ubude be-focal lensi, (c) amandla elensi.
Amalensi ezibuko ngokuvamile aqhele ngamasentimitha amabili ukusuka emehlweni.
Ingxoxo
(A) Uhlobo lwelensi esetshenzisiwe
Ngesihloko ukubona kude Kuye kwachazwa ukuthi amalensi asetshenziselwa ukulungisa amehlo aseduze angamalensi aqondile noma amalensi ahlanganisiwe noma amalensi amahle.
(B) Ubude bokugxila kwelensi
Ukuze into ibonwe ingamasentimitha angama-25 phambi kweso, ilensi kumele yakhe isithombe ebangeni elingamasentimitha ayi-102 phambi kweso, okuyiphuzu eliseduze kweso elibona eduze. Ilensi yengilazi ingamasentimitha ama-2 ukusuka esweni, ngakho isithombe kumele sibe ngamasentimitha ayi-100 phambi kwelensi, kanti into kumele ibe ngamasentimitha angama-23 phambi kwelensi. Isithombe siphambi kwelensi, ngakho isithombe siqondile futhi singokoqobo (qhathanisa incazelo esihlokweni). isithombe selensi eqondile)
I-Diketahui :
Ibanga lento = 23 cm
Ibanga lesithombe (s') = -100 cm (elibi ngoba liyi-virtual)
Kubuziwe : Ubude be-focal (f)
Jawab :
1/f = 1/s + 1/s'
1/f = 1/23 + 1/-100
1/f = 1/23 – 1/100
1/f = 100/2300 – 23/2300
1/f = 77/2300
f = 2300/77 = 30 cm = 0,3 amamitha
Ubude obuqondile bokugxila busho ukuthi ilensi esetshenziswayo ilensi eqondile noma ilensi ehlanganisiwe noma ilensi enhle.
(C) Amandla ngelensi
P = 1/f = 1/0,3 = +3 Ama-Diopters
Amandla noma amandla elensi angu-+3 D. Uphawu oluhle lusho ukuthi ilensi esetshenzisiwe ilensi ehlanganisiwe noma ilensi ehlanganayo.
