PURPOSE Evaluation of improving near vision in presbyopic patients with low to moderate myopia with selective treatment of high-order aberrations (HOAs) using the ORK-CAM software aberrometer and a SCHWIND ESIRIS excimer laser. In this study, all HOAs except vertical coma were treated and the effect on near visual function was evaluated. SETTING Horus Vision Correction Center, Alexandria, Egy...

The clinical importance of peripheral refraction as a function accommodation has become increasingly evident in the last years with special attention given to myopia control. Low order ocular aberrations were measured Hartmann–Shack aberrometer sample 28 young emmetropic subjects. A stationary Maltese cross was presented at 2.5 D and 5.0 accommodative demand 0°, 10° 20° eccentricity horizontal ...

We present an algorithm to extend significantly the dynamic range of a Shack-Hartmann wavefront sensor. With this method, the recorded Shack-Hartmann spots are not constrained to stay in the field of view of their lenslet. The proposed algorithm is computationally effective, robust to a high level of noise on the measured centroid positions and also to missing centroid values. The principle is ...

RAY OPTICS DESCRIPTION Nearly 400 years ago, the celebrated Jesuit philosopher-astronomer, Christopher Scheiner, professor at the University of Ingolstadt, demonstrated the focusing ability of the human eye using a simple device known as the Scheiner Disk.1 Scheiner's experiments showed that if an optically imperfect eye views through an opaque disk perforated with two pinholes, a single distan...