The monochromatic aberrations present in the eyes of a group of 21 young myopic subjects and 16 young emmetropic subjects were measured along the visual axis at three levels of accommodation. The aberrations were measured using a modified aberroscope technique which makes use of a retinal camera to photograph the shadow image of the aberroscope grid on the retina, while accommodation levels of ...

surgery-induced change of corneal aberrations Computerized videokeratography — which measures the shape of the cornea, typically by analysis of the distortion of concentric rings projected on it—is routinely used in clinics to evaluate surgical results (i.e., centration and location of the treatment zone and characteristic patterns of what is known in clinical terms as irregular corneal astigma...

PURPOSE To determine the distribution of Zernike coefficients and higher order aberrations in a normal population and its relationship with age, gender, biometric components, and spherical equivalent. METHODS During the first phase of the Shahroud cohort study, 6311 people of the 40-64-year-old population of Shahroud city were selected through random cluster sampling. A subsample of participa...

High contrast coronagraphic imaging of the immediate surrounding of stars requires exquisite control of low-order wavefront aberrations, such as tip-tilt (pointing) and focus. We propose an accurate, efficient and easy to implement technique to measure such aberrations in coronagraphs which use a focal plane mask to block starlight. The Coronagraphic Low Order Wavefront Sensor (CLOWFS) produces...

PURPOSE To compare higher order aberrations measured with the NIDEK OPD-Scan and AMO WaveScan. METHODS Third- to sixth-order higher order aberrations were measured in 1072 eyes using the OPD-Scan and WaveScan. Means, standard deviations, confidence intervals, limits of agreement, and intraclass correlation coefficients (ICC) were calculated. RESULTS Aberrations of greatest magnitude with th...

Higher-order aberration correction in abnormal eyes can result in significant vision improvement, especially in eyes with abnormal corneas. Customized optics such as phase plates and customized contact lenses are one of the most practical, nonsurgical ways to correct these ocular higher-order aberrations. We demonstrate the feasibility of correcting higher-order aberrations and improving visual...

The aberrations of the objective lens should be measured and adjusted to realize high spatial resolution in scanning transmission electron microscopy (STEM). Here we report a method of measuring low-order aberrations using the Fourier transforms of Ronchigrams of an arbitrary crystal such as a specimen of interest. We have applied this technique to measure first- and second-order geometrical ab...

PURPOSE To determine objectively the changes in the ocular aberrations (3rd order and above) induced by myopic LASIK refractive surgery and its impact on image quality. METHODS The ocular aberrations of 22 normal myopic eyes (preoperative refraction ranged from -13 to -2 D) were measured before (2.9 +/- 4.3 weeks) and after (7.7 +/- 3.2 weeks) LASIK refractive surgery using a laser ray tracin...

PURPOSE To determine how refractive error, visual acuity, and high-order aberrations (3rd- and 4th-order) are affected by the formation of a lamellar corneal flap during laser in situ keratomileusis (LASIK). SETTING University refractive surgery center. METHODS The effect of lamellar corneal flap formation was analyzed in 15 myopic eyes (mean preoperative refraction -4.72 diopters [D] [rang...

PURPOSE To evaluate relationships among contrast sensitivity function, ocular higher-order aberration, and myopic correction in eyes undergoing overnight orthokeratology for myopia. METHODS A prospective study was conducted in 46 eyes of 23 patients undergoing orthokeratology. Inclusion criteria were spherical equivalent refraction between -1.00 and -4.00 diopters (D), refractive astigmatism ...