A bifocal ndi lens yomwe ili ndi mfundo ziwiri, kawirikawiri lens imodzi poyang'ana zinthu zakutali, ndi lens limodzi kuti ayang'ane zinthu zakufupi. A bifocal amadziwikanso ngati lens multi focal lens. Ben Franklin akutchulidwa kuti ndi amene anayambitsa lenti yoyamba ya bifocal.
Chifukwa Chimene Muyenera Kufunikira Bifocal
Presbyopia: Zimakhala zovuta kumvetsa mpaka mutakwanitsa nthawi imeneyo m'moyo wanu, koma pofika zaka 40, timakhala ndi chitukuko.
Presbyopia amachititsa kuchepa pang'ono kuti athe kuganizira zinthu pafupi ndi kuwerenga zochepa. Poyamba, anthu amawona kuti kuli kovuta kuwerengera kumalo ozizira ndikuwerenga kukula kwa botolo la mankhwala. Anthu omwe ali ndi presbyopia amadziwanso kuti n'kovuta kuganizira kutali ndi pafupi. Pamene nthawi yochuluka ikupita ndipo ayandikira pafupi zaka 42 mpaka 45, imayamba kukhala nkhani yaikulu kwambiri pamoyo wawo komanso zonse zomwe amayesa kuziwerenga kapena kuyang'ana kumapeto zimakhala zovuta kwambiri. Madokotala samvetsetsa ndondomekoyi koma amakhulupirira kuti mankhwalawa amayamba chifukwa cha kuphatikiza thupi lopanda maso mkati mwa diso lomwe silingagwire ntchito komanso disolo liri mkati mwathu, ndikukhala osasintha. Zonsezi ndizosalephera kuthetsa zinthu pafupi. Yankho la vuto ili ndi la optometrist lanu kuti lifotokoze bifocal. Panthawi imeneyi, tikusowa gawo limodzi la lens kuti tiganizire patali ndi gawo limodzi kuti tiganizire pafupi.
Kulephera Kuthandizira: Anthu ena amafunikira bifocal ndi chifukwa chosowa ntchito . Ana ena amakhala ndi vuto limene sangathe kuganizira mosavuta kutali ndi pafupi. Amakhalanso otopa kwambiri pamene akuyesera kuti azikhala patsogolo pa kuwerenga kapena kuphunzira mukalasi.
Esotropia yokhazikika: Chifukwa china chimene ana ena amafunikira kuvala bifocal ndi chifukwa cha vuto lotchedwa accommodative esotropia. Esotropia yokhazikika ndi imodzi mwa mitundu yowonjezereka ya strabismus. Kawirikawiri, ana awa ali kutali kwambiri. Ana awa ali ndi esotropia kapena diso loyang'aniridwa chifukwa cha kuyang'ana kwa maso pamene akuyesera kuwonetsa bwino ndikuwonekeratu. Iwo ali ndi kusiyana pakati pa minofu ya maso yowonongeka ndi dongosolo. A bifocal nthawi zambiri amachepetsa vuto lonse.
Mitundu ya Mafilimu A Bifocal
Mafilimu a Bifocal amapezeka m'mitundu yosiyanasiyana.
- Chipinda chapafupi - Chipinda chophwanyika pamwamba bifocal chili ndi kachigawo kakang'ono kofanana ndi theka la mwezi kapena kalata "D" kumbali yake. Imaikidwa pamtunda ndi pansi kumunsi kwa disolo. Malingana ndi zokonda, wodwala akhoza kusankha pakati pa 25 mm gawo kapena gawo la 28 mm. Mbali ya gawo ili ndi mzere wowonekera mu lens.
- Zomwe zimagwirira ntchito - Pakatikatikatikati mwa lentilo ndizungu 22 kapena 24 mm kuzungulira. Izi zimapangidwa kuti zilole kuti wobwerayo afikire gawo lowerenga la gawo mosavuta. Zigawo zozungulira sizinali zobvala lero.
- Kuphatikizidwa - mbali zofiira zapadera zinkatchuka kwambiri asanayambe kugwiritsidwa ntchito. Zimakhala zopangidwa ndi gawo lozungulira pomwe m'mphepete mwake zimagwirizanitsidwa ndi diso lonse. Ngakhale katswiri wodziŵa zamagetsi amatha kuziwona mosavuta, kudziko lonse lapansi sichioneka chowoneka ngati chipinda chophwanyika pamwamba.
- Executive - An executive bifocal ndi mzere bifocal pomwe mbali yapamwamba (kutalika) mbali ya lens imasiyanitsidwa kwathunthu ndi theka lafupi (pafupi) mbali ya lens ili ndi lens loonekera yomwe ikuyenda njira yonse kudutsa lens. Awa anali otchuka kwambiri ndi anthu omwe ankagwira ntchito zambiri ndi desiki ntchito pa ntchito yawo ndipo ankaganiziridwa kuti aziwapatsa malo ambiri omwe angaganizire. Iwo akhala osakondwera kwambiri muzaka zaposachedwapa chifukwa cha mzere wosayang'ana womwe ukuyenda njira yonse kudutsa pa lens. Komanso, akatswiri opanga mawonekedwe adadziwa kuti anthu sanagwiritse ntchito malingaliro ambiri m'dera laling'ono monga momwe lingaliro limodzi ndi chiphalaphala cha bifocal chinapangidwanso.
- Kupita patsogolo - Mapuloteni opita patsogolo ndi mandala kuti mumve kuti amalengezedwa ngati osaoneka, osagwedezeka kapena opanda mzere bifocal. Mapulogalamu opita patsogolo amawonjezereka pang'ono kapena kusintha mwa mphamvu yakuwerenga pamene disolo limatsikira kumunsi kwa disolo popanda mizere yowoneka. M'malo mokhala wochotsa mofulumira kutali ndi pafupi, pali kusintha kochepa pang'ono mu mphamvu. Mapulogalamu apamtima chifukwa amadziwika mofulumira chifukwa amapereka mawonekedwe aunyamata.