 Although other spiders can also jump , salticids including P. schultzi have significantly better vision than other spiders , : 521 and their main eyes are more acute in daylight than a cat 's and 10 times more acute than a dragonfly 's . Jumping spiders have eight eyes , the two large ones in the center @-@ and @-@ front position ( the <unk> eyes , also called " principal eyes " : 51 ) housed in tubes in the head and providing acute vision . The other six are secondary eyes , positioned along the sides of the carapace and acting mainly as movement detectors . : 16 In most jumping spiders , the middle pair of secondary eyes is very small and has no known function , but those of Portia are relatively large , and function as well as those of the other secondary eyes . : 424 : 232 Jumping spiders ' main eyes can see from red to ultraviolet . 
