Central and near peripheral retinal contributions to the depth-of-focus using naturalistic stimulation

Although the depth-of-focus (DOF) has been investigated separately in the central retina and in the near retinal periphery, knowledge about their combined relative contribution to overall blur perception has remained unknown. In the present study, the DOF was measured psychophysically with a naturalistic pictorial stimulus as a function of spatial extent across the near retinal periphery under monocular Badal viewing conditions with accommodation paralyzed. The group mean total DOF progressively increased linearly with target size. Based on the individual DOF responses, the group was categorized into two subgroups: a predominantly centrally-driven and a centrally plus peripherally-driven subgroup. The results implicated partial cone pooling of blur information, as well as influence from perceptual, attentional, and optical aspects. However, the subgroup response profiles suggested individual differences in the weighting of the near peripheral blur information at the retinal level, and perhaps at higher-level areas of the visual system, involving spatial integration and global attentional processing.