Adaptive optics reveal role for spherical aberration in improving binocular vision in monovision

Studies using adaptive optics show that holding monovision to no more than 1.5 dioptres power difference between the two eyes while introducing a slight positive spherical aberration in the non-dominant eye greatly improves binocular vision, Scott M MacRae MD told the ESCRS Symposium at the AAO.

Dr MacRae used one of only two binocular adaptive optics systems in the world to detect and correct aberrations in test subjects’ eyes. This allowed objective analysis of visual performance, including visual acuity and contrast sensitivity for each eye and binocularly, as well as stereoacuity, under a variety of correction scenarios.

Binocular vision up to 1.25 to 1.50 dioptres difference between the dominant and non-dominant eyes, but actually worse than monocular vision with higher power difference, Dr MacRae said. Inducing a modest amount of positive spherical aberration in the non-dominant eye increased depth of field, which improved intermediate vision.

Correcting the dominant eye for best distance vision optical quality resulted in better visual acuity and contrast sensitivity at all distances, Dr MacRae said. However, a very small amount of spherical aberration in the dominant eye also improved binocular summation, further improving binocular visual performance at all distances.