Letter to the Editor

Abstract

Dear Editor, We read with interest the recent study by Leube and colleagues (2017) that shows the effect of real defocus blur (where a clear target was presented with blur induced optically with lenses of different power) and simulated defocus blur (where a blurred target was presented without optical blur) on the visual acuity (VA) under monochromatic light conditions. The key difference between the two conditions is that, with optical blur, the light rays reach the retina with some optical vergence (converging if the lens is negative; diverging if the lens is positive), whereas, with target blur, optical vergence is always zero and the computationally blurred target is presented focused at the retina