Bifocal and Multifocal Contact Lenses for Presbyopia and Myopia Control

Figure 4

Through-focus Visual Strehl for the theoretical diffraction-limited eye (dashed) and the aspheric design (solid) for 4 mm pupil diameter and different light level conditions: 1000 cd/m², 10 cd/m², and 1 cd/m². Threshold for acceptable vision.