The eye is a complex organ that plays a key role in how an animal perceives and responds to its environment. Eye size, in particular, is a large determinant of an animal’s visual capabilities, where visual capabilities tend to improve with increasing eye size. Many studies have shown that eye size correlates with habitat and behavior across multiple taxonomic groups. Recently, a few studies have also demonstrated that visually-guided predators may target a conspicuously pigmented eye, thus constraining eye size in some species. To better understand the role of visually-guided predation in shaping eye size we evaluate phenotypic plasticity in a small freshwater crustacean, Daphnia. Here, we tested the “visual target hypothesis” which predicts that the eye size of a Daphnia exposed to predation cues will be significantly smaller than Daphnia exposed to no predation cues. This study was performed by exposing four species of Daphnia with chemical cues from Gambusia affinis or no chemical cues. Eye diameter and body length measurements were taken throughout the study in order to calculate relative eye sizes. Our results showed that relative eye size was not affected by the predatory cues, but absolute body size was. Therefore, the visual target hypothesis was not supported in our study.