Abstract
Critical flicker fusion threshold (CFFT) is the lowest level of continuous flicker that is perceived as a steady source of light. Macular pigment optical density (MPOD) is a measure of retinal concentrations of lutein and zeaxanthin (antioxidants acquired from diet). Recent research suggests that MPOD may be related to critical flicker fusion frequency (CFF). Furthermore, a recent investigation concluded that CFF thresholds are highly related to dorsal stream processing. This study was designed to investigate the possible relationship between MPOD and cortical processing. Hyperacuity, the finest spatial discrimination possible for the human visual system, was chosen as a measure of cortical processing as it demonstrates clear improvement effects with training. Fourteen subjects were recruited from the University of Georgia. Hyperacuity was recorded across time using a pair of black vernier lines against a white background. MPOD was assessed using a macular pigment metrics densitometer. The results of this study indicate that individuals with higher MPOD demonstrate improvements in hyperacuity faster than individuals with lower MPOD. These results suggest that MPOD is influencing cortical processing.