眼尖

to have good eyes

eye / small hole / crux (of a matter) / CL:隻|只[zhi1],雙|双[shuang1] / classifier for big hollow things (wells, stoves, pots etc)

point (of needle) / sharp / shrewd / pointed

pointed; tapering; sharp / (of a sound) shrill; piercing / (of one's hearing, sight etc) sharp; acute; keen / to make (one's voice) shrill / sharp point; tip / the best of sth; the cream of the crop