Spherical aberration yielding optimum visual performance: Evaluation of intraocular lenses using adaptive optics simulation

PURPOSE: To evaluate the influence of spherical aberration on contrast sensitivity using adaptive optics. SETTING: Vision Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California, Davis Medical Center, Sacramento, California, USA. METHODS: Contrast sensitivity at 8 cycles per degree was evaluated using an adaptive optics system that permitted aberrations to be measured with a Hartmann‐Shack wavefront sensor and controlled by a 109 actuator continuous‐surface deformable mirror that was at a plane conjugate to the observer's pupil. Vertical Gabor patches were viewed through a 6.3 mm diameter pupil conjugate aperture. Contrast sensitivity was measured with the deformable mirror set to produce 1 of 5 spherical aberration profiles (−0.2 to +0.2 μm). Contrast sensitivity over the range of spherical aberration was fitted with a polynomial function. RESULTS: Three subjects (age 21 to 24 years) participated. The measured total mean spherical aberration resulting from the spherical aberration profiles produced by the deformable mirror was between −0.15 μm and +0.25 μm. The peak contrast sensitivity of this function for the 3 subjects combined occurred at +0.06 μm of spherical aberration. The peak contrast sensitivity was also achieved with positive spherical aberration for each subject's data fitted individually (mean 0.09). CONCLUSION: There was intersubject variability in the measurements; however, the mean visual performance was best with the introduction of a small positive spherical aberration.