Ubwino wa mandala osintha mtundu ndikuti m'malo akunja adzuwa, mandala amasinthidwa pang'onopang'ono kuchoka ku mtundu wopanda utoto kupita ku imvi, ndipo atabwerera m'chipindacho kuchokera ku chilengedwe cha ultraviolet ndikubwerera pang'onopang'ono ku mtundu wopanda utoto, kumathetsa vuto la kuvala magalasi adzuwa. myopia, ndipo imakwaniritsa ziwiri zamkati ndi zakunja.