Considering the great popularity of amusement machines and contact lens that magnify the iris, it is clear that eyes play a significant role in facial attractiveness. However, there have been few studies that investigated attractiveness using average faces while manipulating the size of the iris and the shape of eyelid. In this study, we generated average female faces with either flat or double eyelids, we also generated four patterns of the size of the iris, and asked participants to rate their attractiveness and how natural or otherwise the faces appeared. The research found a face with flat eyelids and an iris at 125% of normal size was judged more attractive and more natural than faces with double eyelids. These results suggest that females with flat eyelids can readily enhance their facial attractiveness utilizing commodities such as contact lens that magnify the iris.