Although the human eye has a relatively simple optical system, it is not perfect. It has been well known that the human eye suffers from the wavefront aberration that includes both lower (defocus and astigmatism) and higher order aberrations. The lower order aberration has been effectively corrected with conventional ophthalmic lenses such as spectacles and contact lenses. However, it is more c...

PURPOSE To evaluate the correlation between refractive error and higher-order aberrations (HOAs) in patients with myopic astigmatism. METHODS HOAs were measured using the Zywave II aberrometer over a 6 mm pupil. Correlations between HOAs and myopia, astigmatism, and age were analyzed. RESULTS One hundred and twenty-six eyes of 63 subjects with mean age of 26.4±5.9 years were studied. Mean s...

The wave-front aberration of the human eye was measured for eight subjects using a spatially resolved refractometer (a psychophysical ray-tracing test). The eyes were undilated and presented with accommodative stimuli varying from 0 to -6 diopters. Monochromatic wave-front aberrations tend to increase with increasing levels of accommodation, although there are substantial individual variations ...

The ideal location for an aberration corrector in an electron-optical column is at the place where the aberration is introduced. In practice, this of course typically cannot be achieved. The resultant separation between where an aberration is introduced and where it is removed produces combination aberrations for all aberrations of higher than first order. In the case of third-order aberration ...

PURPOSE To define the corneal optics of conductive keratoplasty (CK) and assess the clinical implications for hyperopia and presbyopia management. METHODS Four analyses were done. (1) Multifocal effects: In a prospective study of CK, uncorrected visual acuity (UCVA) for a given refractive error in 72 postoperative eyes was compared to control eyes. (2) Surgically induced astigmatism (SIA): 20...

The ideal location for an aberration corrector in an electron-optical column is exactly at the place where the aberration to be corrected is introduced. In practice, this of course cannot be achieved. The resultant separation between where an aberration is introduced and where it is removed produces combination aberrations for all aberrations of higher than first order. A case of particular imp...