Pupil Diameter and the Depth-of-field of the Human Eye as Measured by Laser Speckle

Results are given for the variation in the depth-of-field with entrance pupil diameter for six subjects. The method was based on observation of a laser speckle pattern at 633 nm on the surface of a slowly rotating drum. Depth-of-field falls with pupil diameters up to ∼ 5 mm and then remains at an approximately constant value. The roles of diffraction, aberration, the Stiles-Crawford effect and of non-optical aspects of the visual system are discussed.