jamani mtu kama huyu utakuta active part ni moja na kama zikiwa zote mbili basi kuna itakayo kuwa weak kuliko mwenzie.pupils zote mbili haziwez kuwa na the same efficiency. but kazi ya kuona iko kama tu ya jicho la kawaida siyo kwamba usiku atakuwa anaona la hasha kwani rods na cons ziko na specific jobs.