Mukalowa m'sitolo ya magalasi ndikuyesera kugula magalasi, mumakhala ndi mitundu ingapo ya magalasi omwe mungasankhe malinga ndi zomwe mwalemba. Koma anthu ambiri amasokonezeka ndi mawu akuti masomphenya amodzi, bifocal ndi kupita patsogolo. Mawuwa amanena za momwe magalasi a magalasi anu amapangidwira. Koma ngati simuli otsimikiza za mtundu wa magalasi omwe mankhwala anu amafunikira, nazi mwachidule zomwe zingakuthandizeni kuti muyambe.
1. Kodi Magalasi a Masomphenya Amodzi Ndi Chiyani?
Diso la masomphenya amodzi kwenikweni ndi lens lomwe limakhala ndi mankhwala amodzi. Magalasi amtunduwu amagwiritsidwa ntchito popereka mankhwala kwa anthu omwe amawona chapafupi, owonera patali, omwe ali ndi astigmatism, kapena omwe ali ndi zolakwika zosiyanasiyana. Nthawi zambiri, magalasi a masomphenya amodzi amagwiritsidwa ntchito ndi anthu omwe amafunikira mphamvu zofanana kuti awone kutali ndi kutseka. Komabe, pali magalasi a masomphenya amodzi omwe amaperekedwa kwa cholinga china. Mwachitsanzo, magalasi owerengera omwe amagwiritsidwa ntchito powerenga okha amakhala ndi masomphenya amodzi.
Masomphenya ang'onoang'ono ndi abwino kwa ana ambiri komanso achikulire chifukwa nthawi zambiri safunikira kusintha mawonekedwe awo potengera kutalika kwawo. Dongosolo lanu la magalasi a masomphenya amodzi nthawi zonse limaphatikizapo gawo lozungulira ngati nambala yoyamba pamankhwala anu ndipo lingaphatikizepo chigawo cha silinda chowongolera astigmatism.
2. Kodi Ma Lens a Bifocal ndi Chiyani?
Ma lens a Bifocal ali ndi magawo awiri osiyana owongolera masomphenya. Maderawa amagawidwa ndi mzere wosiyana womwe umakhala mopingasa kudutsa ma lens. Kumwamba kwa mandala kumagwiritsidwa ntchito patali, pomwe pansi kumagwiritsidwa ntchito poyang'ana pafupi. Gawo la lens lomwe limayikidwa pafupi ndi masomphenya likhoza kupangidwa m'njira zingapo zosiyana: gawo la D, gawo lozungulira (lowoneka / losawoneka), gawo lopindika ndi E-line.
Magalasi a Bifocal amagwiritsidwa ntchito ngati wina ndi wosowa kwambiri yemwe sangathe kuzolowera magalasi opita patsogolo kapena mwa ana aang'ono omwe maso awo amadutsana akawerenga. Chifukwa chomwe akucheperachepera ndi chakuti pali vuto lomwe limayambitsidwa ndi ma lens a bifocal otchedwa "image jump", momwe zithunzi zimawoneka ngati zikudumpha maso anu akuyenda pakati pa magawo awiri a mandala.
3. Kodi Magalasi Opita Patsogolo Ndi Chiyani?
Mapangidwe a magalasi opita patsogolo ndi atsopano komanso apamwamba kuposa ma bifocal. Magalasiwa amapereka mphamvu yowonjezereka kuchokera pamwamba pa disolo mpaka pansi, ndikupereka kusintha kosasinthika kwa zosowa zosiyanasiyana za masomphenya. Magalasi agalasi opita patsogolo amatchedwanso a no-line bifocal chifukwa alibe mzere wowonekera pakati pa magawo, zomwe zimawapangitsa kukhala osangalatsa kwambiri.
Komanso, magalasi opita patsogolo amathandizanso kuti pakhale kusintha kosalala pakati pa mtunda, wapakati, ndi pafupi ndi gawo la mankhwala anu. Gawo lapakati la mandala ndiloyenera kuchita zinthu zapakatikati monga ntchito yapakompyuta. Magalasi opita patsogolo ali ndi mwayi wopanga makonde aatali kapena amfupi. Khola ndi gawo la mandala lomwe limakupatsani mwayi wowona mtunda wapakati.
Mwachidule, masomphenya amodzi (SV), bifocal, ndi ma lens opita patsogolo aliyense amapereka mayankho owongolera masomphenya. Magalasi owonera amodzi amawongolera mtunda umodzi (pafupi kapena kutali), pomwe magalasi owoneka bwino amayang'ana pafupi ndi kutali mu lens imodzi. Ma Bifocals ali ndi mzere wowoneka wolekanitsa magawo apafupi ndi mtunda, pomwe magalasi opita patsogolo amapereka kusintha kopanda msoko, komaliza pakati pa mtunda wopanda mzere wowonekera. Ngati mukufuna zina zambiri, chonde omasuka kulankhula nafe.