This study aims to examine the specific effect that 3D game play has on the control of the eyes horizontal movements. It will examine the youngest group of consumers this technology is marketed to, 7 to 11-year-olds and no children under 7 years of age will be recruited to this study as per Nintendo's hardware guidelines, which recommends that children under 7 years of age not play in 3D mode. It will examine the effect of playing in 3D for 30 minutes on horizontal fusional amplitudes compared with a control group playing in 2D for 30 minutes.