We thank Galvis and associates for their interest in our article and their thoughtful comments. They suggested that the amount of change in corneal higher-order aberrations with age is less than that in total ocular higher-order aberrations, and corneal spherical aberration (SA) is stable with age. They also stated that high mesopic conditions (8 lux) are rather uncommon in normal life. Therefore, more than 10% of the eyes would show smaller pupil size than the minimum effective diameter.
We agree that the increment of corneal higher-order aberration with age is less than that of ocular higher-order aberration. The increase of corneal higher-order aberration alone cannot explain the reduction of retinal image quality with age because corneal aberration is just a part of ocular aberration. We also agree that corneal SA is relatively stable with age. Therefore, aspheric intraocular lenses (IOLs) with a fixed amount of negative SA have been used to compensate the stable positive corneal SA.
Our study tried to evaluate the minimum pupil diameter for each aspheric IOL to be effective. As they mentioned, more than 10% of the eyes showed smaller pupil size than the minimum effective diameter in less strict mesopic conditions. Although they wrote that the illumination in the street in front of their clinic ranged between 13 and 15 lux and a level of 8 lux is rather uncommon in normal life, the actual level of road lighting at night was between 0.5 and 10 lux. We think that a level of 8 lux is not too low for the studies to evaluate the effectiveness of aspheric IOL.
They also wrote that they could not find differences on contrast sensitivity between aspheric and spheric IOLs because of their patients’ small pupils. We agree with their result. Therefore, the pupil diameter should be considered when evaluating the effectiveness of aspheric IOLs, as we mentioned in our article.
Regarding optimal SA after cataract surgery, much more still remains to be done, as they mention.