Depth-of-focus of the human eye in the near retinal periphery

Although the depth-of-focus in the foveal region has been well investigated, knowledge regarding the effect of retinal eccentricity on blur detection and sensitivity is limited. In the present study, the depth-of-focus at the fovea and in the near retinal periphery (0degrees-8degrees) was assessed psychophysically in 7 human subjects using a 5 mm artificial pupil with accommodation paralyzed. The group mean total depth-of-focus progressively increased linearly from 0.89 D at the fovea to 3.51 D at a retinal eccentricity of 8degrees at the rate of 0.29 D/degree, with response variability (S.E.M.) remaining relatively constant (+/-0.17 D). We speculate that the reduced detection and sensitivity to blur in the near periphery may be attributed to retinal topography, sharpness overconstancy, optical aberrations, and visual attention in peripheral vision. (C) 2004 Elsevier Ltd. All rights reserved.