A large variation in both histological and optical data in the previous reports might be in part due to inter-individual differences in the size of the eye, but also from measurement errors (see Section 4). Since the plane in which the lens focuses an image may profoundly influence the range estimation abilities of the larva, it is indispensable to improve the accuracy of both morphological and optical measurements in the large eyes. In the present study morphological and optical properties of the large stemma were examined in the larva of the tiger beetle (Cicindela chinensis) with improved methods. The results are discussed with reference to previous physiological and behavioral works on this larva.