 The adults of the star 's most intelligent species , called cheela ( no flexion for gender or number ) , have about the same mass as an adult human . However , the extreme gravity of Dragon 's Egg compresses the cheela to the volume of a sesame seed , but with a flattened shape about 0 @.@ 5 millimeters ( 0 @.@ 020 inches ) high and about 5 millimeters ( 0 @.@ 20 inches ) in diameter . Their eyes are 0 @.@ 1 millimeters ( 0 @.@ 0039 inches ) wide . Such minute eyes can see clearly only in ultraviolet and , in good light , the longest wavelengths of the X @-@ ray band . 
