Technique and Device for Measuring the Human Eye’s Depth of Focus
In this paper, we demonstrate that the depth of focus (DOF) of the eye’s optical system during implantation of intraocular lenses and aberration correction of presbyopian eyes should be identified and measured. The known methods and devices are described to determine the pseudo-accommodation volume of presbyopic eyes by subjective and objective methods. Their advantages and disadvantages are analyzed. We show that the main disadvantage of subjective methods is the impossibility to separate a pseudo-accommodation component caused by the eye’s optics from its total volume. The disadvantage of the objective method based on results of eye aberrometry is an extremely complicated and cumbersome mathematical procedure of evaluating the DOF. The method and device are proposed for objective measurement of geometric parameters of the DOF deprived of the above-mentioned deficiencies. This method is based on the image analysis of the luminous point on the retina in the reverse light. A scheme was shown for the device that allows to scan the “air” image in a short period of time.