Ndili ndi zaka zokumana nazo mu zojambula zapamwamba za photopter Ce & FDA , MPHAMVA CISONKHANO LABWINO KWAMBIRI CE & FDA . IVYAMENEYAMILARD FRECTE CE CRA / FDA yokhudza panthawi yapamwamba ya Phoropster Ce & FDA . Kuphatikiza pa mndandanda wazomwe zili pansipa, mutha kusinthanso mtundu wanu wapadera wa phoropter wapadera wa Phordopter .