Magalasi a Bifocal amatha kutchedwa mandala ambiri.Ili ndi magawo awiri a masomphenya mu lens imodzi yowoneka.Lens yayikulu nthawi zambiri imakhala ndi malangizo ofunikira kuti muwone patali.Komabe, izi zitha kukhalanso mawu anu oti mugwiritse ntchito pakompyuta kapena zapakati, chifukwa nthawi zambiri mumayang'ana molunjika mukamawona gawo ili la lens. Mbali yapansi, yomwe imatchedwanso zenera, nthawi zambiri imakhala ndi malangizo anu owerengera.Popeza nthawi zambiri mumayang'ana pansi kuti muwerenge, awa ndi malo abwino oti muyikepo chithandizo cha masomphenya awa.
Ubwino wa mandala apamwamba kwambiri a bifocal.
1.Iyi ndi mtundu wosavuta kwambiri wa lens umene umalola wovalayo kuganizira zinthu zonse zomwe zili pafupi ndi kutali kudzera mu lens imodzi.
2.Magalasi amtundu uwu amapangidwa kuti azitha kuyang'ana zinthu patali, pafupi ndi mtunda wapakatikati ndi kusintha kofanana kwa mphamvu pa mtunda uliwonse.
Ubwino wa ma bifocals ozungulira
1.Ovala amatha kuona zinthu zapafupi ndi mawonekedwe ozungulira ndikuwona mtunda wa zinthu ndi magalasi ena onse.
2.Ovala safuna kusintha magalasi awiri osiyana masomphenya pamene onse kuwerenga buku ndi kuonera TV.
3.Ovala amatha kusunga mawonekedwe omwewo pamene akuyang'ana zonse zapafupi kapena zakutali.
Ngati mumayamikira khalidwe, machitidwe ndi luso mwafika pamalo oyenera.
Index&Zinthu Zilipo
 Zakuthupi | Mtengo wa NK-55 | Polycarbonate | MBU-8 | MR-7 | MR-174 |
 Refractive Index | 1.56 | 1.59 | 1.60 | 1.67 | 1.74 |
 Mtengo wa Abbe | 35 | 32 | 42 | 32 | 33 |
 Specific Gravity | 1.28g/cm3 | 1.20g/cm3 | 1.30g/cm3 | 1.36g/cm3 | 1.46g/cm3 |
 UV Block | 385nm pa | 380nm pa | 395nm pa | 395nm pa | 395nm pa |
 Kupanga | SPH | SPH | SPH/ASP | ASP | ASP |
Kodi bifocal lens imagwira ntchito bwanji?
Magalasi a Bifocal ndi abwino kwa anthu omwe akudwala presbyopia - mkhalidwe womwe munthu amawona zosawoneka bwino akamawerenga buku.Pofuna kukonza vutoli la masomphenya akutali ndi pafupi, magalasi a bifocal amagwiritsidwa ntchito.Amakhala ndi magawo awiri osiyana owongolera masomphenya, osiyanitsidwa ndi mzere kudutsa magalasi.Kumwamba kwa mandala kumagwiritsidwa ntchito powona zinthu zakutali pomwe gawo la pansi limakonza masomphenya apafupi.
