Fig. 8From: Scleral surgery for the treatment of presbyopia: where are we today?A representative figure of the effective range of focus (EROF) for an old (59-year-old) eye. Visual Strehl ratio based upon the optical transfer function (VSOTF) is computed as a function of defocus using a through-focus curve. Through-focus curves are shown for distance (green) and near (red)Back to article page