Wave aberrations have been measured in large populations when the eye’s accommodation is relaxed under natural viewing condition or paralyzed with cycloplegic agents (Porter, Guirao, Cox, & Williams,
2001; Thibos, Hong, Bradley, & Cheng,
2002b; Castejon-Mochon, Lopez-Gil, Benito, & Artal,
2002). In an accommodated eye, wave aberrations are expected to change because ocular structures, particularly the shape, position, and refractive index gradient of the crystalline lens change during accommodation (Garner & Yap,
1997; Garner & Smith,
1997; Koretz, Cook, & Kaufman,
2002). In fact, many studies have demonstrated such accommodation-induced changes in aberrations, which include changes of defocus (Ciuffreda,
1991), astigmatism (Millodot & Thibault,
1985; Ukai & Ichihashi,
1991; Mutti, Enlow, & Mitchell,
2001; Tsukamoto, Nakajima, Nishino, Hara, Uozato, & Saishin,
2000), spherical aberration (Ivanoff,
1956; Jenkins,
1963; Koomen, Tousey, & Scolnik,
1949; van den Brink,
1962), and other higher order aberrations (Atchison, Collins, Wildsoet, Christensen, & Waterworth,
1995; He, Burns, & Marcos,
2000; Ninomiya et al.,
2002; He, Marcos, Webb, & Burns,
1998; Howland & Buettner,
1989; Lu, Campbell, & Munger,
1994; Vilupuru, Roorda, & Glasser,
2004).