Changes in the wave aberrations of the crystalline lens due to accommodation are important to understand, especially as they relate to image quality at different viewing distances and the mechanism of accommodation in the eye. A host of studies of the wave aberration of the whole eye have shown that aberrations change with accommodation (Jenkins,
1963; Koomen, Tousey, amp; Scolnik,
1949; Ivanoff,
1956; Atchison, Collins, Wildsoet, Christensen, & Waterworth,
1995; Lu, Campbell, & Munger,
1994; He & Marcos,
2000). Three main results have been found. First, it is suggested that the magnitude of the aberrations change with accommodation in such a way that they reach a minimum at an intermediate level of accommodation. The typical level of accommodation for minimum aberrations was found to be about 2 D, or a 50-cm viewing distance (He & Marcos,
2000). Second, the spherical aberration of the eye tends toward a more negative state as the eye accommodates (Jenkins,
1963; Hofer, Artal, Aragon, & Williams,
2001) (Cheng, Barnett, Vilupuru, Marsack, Kasthurirangan, Applegate, & Roorda,
2004). Measurements along a single meridian of the isolated human crystalline lens undergoing accommodative changes with mechanical stretching have revealed the same trend (Glasser & Campbell,
1999). Finally, the change in aberrations with accommodation is of a similar magnitude as the aberration itself (Williams, Yoon, Guirao, Hofer, & Porter,
2001). These changes in aberrations that occur with accommodation must be dominated by changes in the lens. It is unknown if the changes in aberrations that occur as the eye accommodates are functionally important for vision, or are simply a byproduct of the change in power of the lens. A recent study in monkeys suggests that changes in aberrations serve to accentuate the accommodative changes (Vilupuru, Roorda, & Glasser,
2004). Ocular accommodative aberrations changes limit the benefit of treatments aimed at correcting aberrations of the eye through laser ablation. Understanding the accommodative changes in aberrations of the lens may help to understand how the crystalline lens accommodates, and may also aid in the design of fixed, or accommodating intraocular lens implants.