The present study deals with the use of the dried eye lens weight as an indicator of age in the Egyptian fruit bat. The accuracy of this tool is checked by comparison with some traditional tools used for age determination in bats; ie, forearm length, and the third and fifth digit lengths. Fruit bats in the present study were collected over a period of thirteen months extending from June 2017 to June 2018, inclusive, from the Giza Governorate, Egypt. The whole collection of bats thus includes all possible age categories; ie, young, juveniles, adults, and old adults. The dried eye lenses proved to increase in weight for a longer time of the bat’s life span compared with the other measurements of the body. The use of this weight is thus more suitable for classifying collected bat samples into more relative age classes.