Myopia dani kuwona pafupi ikhoza kusinthidwa pogwiritsa ntchito magalasi a maso dani magalasi olumikizanaMagalasi a magalasi amalumikizidwa ku magalasi, pomwe ma contact lens amalumikizidwa ku diso. Magalasi ali ndi mtunda winawake kuchokera ku diso, pomwe ma contact lens amalumikizidwa ku diso, kotero mtunda pakati pa contact lens ndi diso ndi wochepa.
Nkhaniyi ikufotokoza zitsanzo za mavuto omwe anthu omwe amaona pafupi komanso omwe amaona patali amakumana nawo, mitundu ya magalasi omwe amagwiritsidwa ntchito pokonza masomphenya, komanso kutalika ndi mphamvu za magalasi awa. Nkhaniyi ikufotokoza za kugwiritsa ntchito magalasi olumikizana pokonzanso maso owonera pafupi ndi owonera patali.
Kuwona Pafupi ndi Magalasi Ozungulira
Mtunda wakutali kwambiri womwe munthu wowona pafupi kapena wowona m'maso angaone bwino ndi masentimita 50. Kuti munthu wowona pafupi azitha kuona zinthu patali kwambiri, dziwani (a) mtundu wa lenzi yomwe imagwiritsidwa ntchito, (b) kutalika kwa lenzi ndi mtundu wa lenzi, (c) mphamvu kapena mphamvu ya lenzi.
Magalasi olumikizana ali pafupi kwambiri ndi diso, choncho musanyalanyaze mtunda womwe uli pakati pa lenzi ndi diso. Mtunda womwe uli pakati pa chinthucho ndi chithunzicho ndi lenzi yolumikizana umaganiziridwa kuti ndi wofanana ndi mtunda womwe uli pakati pa chinthucho ndi chithunzicho ndi diso.
Zokambirana
(a) Mtundu wa lenzi yogwiritsidwa ntchito
Pa mutu kuwona pafupi Zafotokozedwa kuti magalasi omwe amagwiritsidwa ntchito pokonza maso owonera pafupi ndi magalasi opindika kapena magalasi osiyana kapena magalasi oipa.
(b) Utali wa lenzi
Chinthu chomwe diso loona pafupi limachiwona kudzera mu lenzi yolumikizana nacho chilibe malire, chifukwa chake lenziyo iyenera kupanga chithunzi pamtunda wa masentimita 50 patsogolo pa lenzi yolumikizana nayo. Chithunzicho chili patsogolo pa lenzi, chifukwa chake chithunzicho ndi chenicheni (yerekezerani kufotokozera kwa nkhaniyi). chithunzi cha lenzi yopingasa)
Ndizodziwika kuti :
Mtunda wa chinthu (s) = wosatha
Mtunda wa chithunzi (s') = -50 cm (woipa chifukwa chithunzicho ndi cha pa intaneti)
Anafunsa Kutalika (f)
Yankhani :
1/f = 1/s + 1/s'
1/f = 1/~ + (- 1/50)
1/f = 0 – 1/50
1/f = – 1/50
f = – 50/1 cm = -50 cm = -0,5 mita.
Kutalika kolunjika kolakwika kumatanthauza kuti lenzi yomwe yagwiritsidwa ntchito ndi mandala opindika kapena magalasi osinthasintha.
(c) Mphamvu ya lenzi
P = 1/f = 1/-0,5 m = -2 Diopta
Mphamvu kapena mphamvu ya lenzi ndi -2 D. Chizindikiro chotsutsa chimatanthauza kuti lenzi yomwe imagwiritsidwa ntchito ndi lenzi yokhotakhota kapena lenzi yosiyana.
Kuwona Pafupi ndi Magalasi Ozungulira
Mtunda wapafupi kwambiri womwe munthu wosawona pafupi angaone bwino ndi 50 cm. Kuti munthu athe kuwerenga pa mtunda wa 25 cm monga diso lachizolowezi, dziwani (a) mtundu wa lenzi yomwe imagwiritsidwa ntchito, (b) kutalika kwa lenzi, (c) mphamvu ya lenzi.
Magalasi olumikizana ali pafupi kwambiri ndi diso, choncho musanyalanyaze mtunda womwe uli pakati pa lenzi ndi diso. Mtunda womwe uli pakati pa chinthucho ndi chithunzicho ndi lenzi yolumikizana umaganiziridwa kuti ndi wofanana ndi mtunda womwe uli pakati pa chinthucho ndi chithunzicho ndi diso.
Zokambirana
(a) Mtundu wa lenzi yogwiritsidwa ntchito
Pa mutu kuwona patali Zafotokozedwa kuti magalasi omwe amagwiritsidwa ntchito pokonza maso owonera pafupi ndi magalasi ozungulira kapena magalasi ozungulira kapena magalasi abwino.
(b) Utali wa lenzi
Kuti chinthu chomwe chikuwonedwa chikhale 25 cm patsogolo pa diso, lenzi iyenera kupanga chithunzi pa mtunda wa 50 cm patsogolo pa diso. Chithunzicho chili patsogolo pa lenzi, motero chithunzicho chili choyima komanso chowoneka bwino (yerekezerani kufotokozera kwa nkhaniyi). chithunzi cha lenzi yozungulira)
Ndizodziwika kuti :
Mtunda wa chinthu = 25 cm
Mtunda wa chithunzi (s') = -50 cm (woipa chifukwa ndi weniweni)
Anafunsa : Kutalika kwa focal (f) kwa contact lens
Yankhani :
1/f = 1/s + 1/s'
1/f = 1/25 + 1/-50
1/f = 2/50 – 1/50
1/f = 1/50
f = 50/1 = 50 cm = 0,5 mamita
Kutalika kwa focal kumatanthauza kuti lenzi yomwe yagwiritsidwa ntchito ndi lenzi yozungulira kapena lenzi yolumikizana kapena lenzi yabwino.
(c) Mphamvu ya lenzi
P = 1/f = 1/0,5 = +2 Diopters
Mphamvu kapena mphamvu ya lenzi ndi +2 D. Chizindikiro chabwino chimatanthauza kuti lenzi yomwe imagwiritsidwa ntchito ndi lenzi yozungulira kapena lenzi yolumikizana.
