• Today, it is widely recognized that implantation of spherical IOLs leads to increased spherical aberrations (SA), therefore decreasing retinal image quality [ 1 ]. (hindawi.com)
  • We showed that SMILE did not induce spherical aberrations. (ekjo.org)
  • Smaller pupil sizes make the eyes less susceptible to spherical aberrations (in which the image appears unfocused) and increase the depth of field, so people don't have to work so hard to focus on the text, which, in turn, means that their eyes are less likely to get tired. (nvadb.com)
  • Wavefront analysis isolates the effect of lower-order aberrations (defocus and astigmatism) and higher-order aberrations as well as the contribution of individual aberrations on optical quality. (hindawi.com)
  • Wavefront analysis technology has enabled physicians to measure higher-order optical aberrations in addition to spherocylinders in clinical practice. (medscape.com)
  • Wavefront describes the curve corresponding to the position of multiple light rays exiting the eye that passed the different spots in the area of the pupil, emanating from the point source in the foveola after it passes through the optical system of the eye. (medscape.com)
  • The local slope of the wavefront curve at the particular spot within the pupil is derived from the actual image displacement of the point source from foveola as it passes through the optical system of the eye as compared to the ideal/predicted image of the ideal optical system. (medscape.com)
  • If it is presumed (that is not entirely true) that the light travels to the eye the same way as out of the eye, the wavefront directly measures the aberrations of the eye. (medscape.com)
  • Ideal wavefront of an optical system with no aberrations in place. (medscape.com)
  • Wavefront analysis instruments do not analyze degradation of the image caused by the chromatic aberrations. (medscape.com)
  • wavefront lasik makes puil size irrelevant? (eyedocnews.com)
  • It would seem the wavefront ablation reduces aberrations. (eyedocnews.com)
  • Visual acuity measurement, manifest refraction, slit-lamp examination, autokeratometry, corneal topography, and evaluation of corneal wavefront aberration were performed preoperatively and at 1 and 3 months after surgery. (ekjo.org)
  • Wavefront-guided excimer laser surgery is designed to minimize surgically induced higher order aberrations or compensate for pre-existing higher order aberrations [ 2 ]. (ekjo.org)
  • A critical property of human vision is that it is imperfect because of the highly influential wavefront aberrations that vary from person to person. (unideb.hu)
  • This study provides an overview of the existing computational image generation techniques that properly simulate human vision in the presence of wavefront aberrations. (unideb.hu)
  • And each minor rod is actually the rays of light or the rays of energy from the retina, and as they pass through the pupillary aperture, there will be several aberrations that they suffer, when they pass through the optical medium of the eye, which produces a composite structure, which can be represented by a composite wavefront. (cybersight.org)
  • PURPOSE: To investigate the influence of pupil and optical zone (OZ) diameter on higher-order aberrations (HOAs) after myopic wavefront-guided laser in situ keratomileusis (LASIK). (lasiksucks4u.com)
  • Wavefront errors were computed for pupil diameters (PDs) of 3.0, 3.5, 4.0, 5.0, 6.0, and 7.0 mm for the individual OZ diameter and for the individual mydriatic PD (7.93 +/- 0.46 mm). (lasiksucks4u.com)
  • CONCLUSION: The OZ zone to pupil ratio (fractional clearance) had a significant impact on HOA induction after wavefront-guided LASIK. (lasiksucks4u.com)
  • A pinhole can reduce not only lower order aberrations, such as sphere and cylinder, but higher order aberrations as well. (bauschsurgical.com)
  • In addition the LOE is free of chromatic aberrations and optical distortions, delivering a high-resolution quality image. (medgadget.com)
  • The refractor should preferably have an apochromatic lens to provide razor sharp views free of chromatic aberration. (cloudynights.com)
  • Or does exit pupil refer to the diameter of the ocular lenses? (birdforum.net)
  • The i.profiler plus (Zeiss, Germany) was used to obtain the manifest refraction(MR) and corneal and ocular aberration in the 5 mm and 3 mm area of the pupil in the half dark room(5~50 lx). (online-koptometry.net)
  • Wang L, Koch DD " Age-related changes in corneal and ocular higher-order aberrations. . (bcm.edu)
  • [ 5 ] If corneal aberrations and irregularities could be reduced after LASIK, then halo, glare, and monocular diplopia also should be reduced. (medscape.com)
  • To investigate clinical outcomes of small incision lenticule extraction (SMILE) including vector parameters and corneal aberrations in myopic patients. (ekjo.org)
  • We analyzed the safety, efficacy, vector parameters, and corneal aberrations at 3 months after surgery. (ekjo.org)
  • Monochromatic aberrations can be subdivided further into spherical refractive error, cylindrical refractive error, spherical aberration, coma, and higher order aberrations. (medscape.com)
  • Since biological structures in the eye contain imperfections, these aberrations are not accounted for by spherical and cylindrical refractive error. (medscape.com)
  • In this study, we investigated the factors that influence the difference in refractive error according to pupil size. (online-koptometry.net)
  • A study using a new infrared imaging technique underscores the need for eye care professionals to fully correct astigmatic refractive errors of 0.75DC or more in soft contact lens wearers for optimal visual acuity (VA), regardless of their pupil size. (opticaljournal.com)
  • VA was reduced with increased pupil size for all three refractive correction methods, attributed to greater aberrations as pupils enlarged. (opticaljournal.com)
  • After adjusting age and sex, spherical aberration(Z 4 0 ) and vertical astigmatism(Z 4 -2 ) were found to affect the difference in SE depending on pupil size. (online-koptometry.net)
  • For example, the normal aberration that is recorded from the human eye can have a component of defocus, astigmatism, coma, triangular astigmatism, and spherical astigmatism. (cybersight.org)
  • Investigators from Eurolens Research at the University of Manchester and CooperVision employed a unique Pupil Control System (PUCS) to precisely specify and control pupil size of study participants during a VA assessment, then characterize the impact of uncorrected astigmatism. (opticaljournal.com)
  • Chromatic aberration is essentially invisible, except for a tiny amount at the very edges of the field, but this is unnoticeable during observing. (astronomics.com)
  • However, what we see in the eyepiece is not a ray spot, but an actual diffraction image deformed by the aberration. (telescope-optics.net)
  • Visual aberrations are the imperfections in human vision, which play an important role in our everyday lives. (unideb.hu)
  • But if there are imperfections of the optical system, as for example in the eye, when there are imperfections in the cornea, in the lens, or any of the conducting media between the cornea to the retina, then the imperfections would be different at different points of time, across the pupils. (cybersight.org)
  • To assess aberrations in the lens, we measure phase deviations between the ideal and the aberrated wavefronts, and scientists have developed rigorous theories-mostly based on spherical surfaces-to address the effects of these imperfections. (spie.org)
  • Optical aberrations are increased because the normal cornea is prolate in shape (steeper in the center), but it becomes oblate (steeper in the periphery) after successful conventional laser ablation profile. (medscape.com)
  • Reducing these 3 major error sources with means available today reduces the MAE to 0.4 D. Using IOLs that compensate for the spherical aberration of the cornea would eliminate the influence of pupil size. (nih.gov)
  • After laser surgery, these aberrations can increase till they start affecting the shape of the cornea. (healthhearty.com)
  • The aberrations due to PRK tend to be lesser than those due to LASIK (laser-assisted in situ keratomileusis), because unlike LASIK, PRK doesn't involve cutting the cornea. (healthhearty.com)
  • 2. Initial corneal curvature - Since the cornea is being flattened, if your cornea starts off relatively flat and must be flattened further, the result could cause problems with aberrations or dryness. (laservue.com)
  • Factors that may rule out LASIK for some patients include large pupils, thin corneas and extremely dry eyes. (wikipedia.org)
  • If you recall, a well-known LASIK surgeon lost a devastating lawsuit a few years ago by a pilot for symptoms that made flying impossible, and I believe his claim was based on his large pupils. (eyedocnews.com)
  • Since the pupil is smaller than the LASIK flap, daytime vision after LASIK is ideal. (freshersnews.co.in)
  • When considering the question of how big the LASIK flap should be, a large flap is good because ablation performed on the epithelium induces aberrations. (ophthalmologytimes.com)
  • Conclusions: Monocular testing induced larger pupil diameters, which was associated with reduced vision compared to binocular measurements in LASIK and non-LASIK patients. (lasiksucks4u.com)
  • While total corneal root mean square higher order aberrations, coma and trefoil showed statistically significant increase, spherical aberration did not show statistically significant change after SMILE. (ekjo.org)
  • A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil. (ekjo.org)
  • The findings give the possibility to synthesize wide-angle lenses with the corrected aberrations of image curvature and meridional coma without geometrical vignetting of wide sloping bunches. (ifmo.ru)
  • On the other hand the failure to accept less illuminance with pupil sizes larger than 3 millimeters is undoubtedly due to the aberrations introduced (akin to fig. 2-5) and to the presence of a Stiles-Crawford effect in photopic vision which reduces the efficiency of the rays from the margin of the pupil. (co.ke)
  • Now, one can calculate the aberrations of the eye either by passing rays of light into the eye, or they can use a laser source, which when reflected from the eye, passes through the lenslet array, and is analyzed after passing through the Hartmann-Shack lenslet into the sensor. (cybersight.org)
  • 9. Ermolaeva E.V., Zverev V.A., Timoshchuk I.N. Interrelation of the aberrations of a broad pencil of rays. (ifmo.ru)
  • Unlike conventional optics, the FoV, eye motion box (the volume in which the eye should be located to view the entire image) and overall size of the optical system are all independent of the LOE thickness. (medgadget.com)
  • With this backdrop in view, this book presents a holistic treatment of topics like paraxial analysis, aberration theory, Hamiltonian optics, ray-optical and wave-optical theories of image formation, Fourier optics, structural design, lens design optimization, global optimization etc. (routledge.com)
  • Recently, Herkommer drew a conceptual picture that the aberration theory of aspherical and freeform optics may be built on the basis of phase-space distributions, in particular, the Wigner distribution function (WDF): the Fourier transform of the coherence function of the wave. (spie.org)
  • 6 With this concept in mind, we examined how the aberrations of a spherical surface affect the WDF, to help predict the corresponding effects of aspherical and freeform optics. (spie.org)
  • Preoperative and postoperative pupil sizes were measured using The Oasis brand of pupillometer, and changes in the pupil size were statistically analyzed. (fortuneonline.org)
  • The mean preoperative pupil size decreased to 4.1 ± 0.9 mm from 4.9 ± 1.0 mm during the first postoperative month. (fortuneonline.org)
  • Dr. Devgan said that the ideal situation is having a flap size that is equal to that of the ablation zone. (ophthalmologytimes.com)
  • Personalized laser correction involves customization of the laser correction program for the purpose of compensating aberrations in the patient's visual apparatus. (erasingdavid.com)
  • The size of the patient's pupil, the profile of the ablations and flap, affect the severity of the aberrations induced during surgery. (healthhearty.com)
  • IOL displacement such as tilt and decentration could not only impair its aberration-correcting effect but may even induce additional optical aberrations [ 4 , 5 ]. (hindawi.com)
  • To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. (hindawi.com)
  • Aberration-correcting aspherical IOLs are aiming to compensate for the corneal spherical aberration of the eye. (hindawi.com)
  • It is known that aspherical lenses significantly decrease higher-order aberrations (HOA) postoperatively [ 1 ]. (hindawi.com)
  • Aberration-free aspherical IOLs follow another concept of aspherical IOL design. (hindawi.com)
  • Our study aimed to evaluate the optical quality and potential benefits on visual outcome of an aberration-free aspherical IOL compared to those of an aspherical IOL with negative SA. (hindawi.com)
  • All subjects underwent complete ophthalmological examination and pupillometry measurements (MonPack One, Vision Monitor System, Metrovision, Perenchies, France) including static and dynamic pupil evaluation. (oftalmoloji.org)
  • Development of a novel dynamic pupil control system to evaluate the impact of uncorrected astigmatic error on visual performance (Read M, et al) was presented at the 2022 American Academy of Optometry annual meeting last week. (opticaljournal.com)
  • For most observers, 7 × 50 (the first number is the magnification, the second is the size of the front lenses in millimetres) or 10 × 50 binoculars may be all that we aspire to for casual astronomical viewing, but the sheer comfort and visual enhancement associated with using both eyes simultaneously could get some of you smitten with a larger binocular as your primary instrument. (astronomynow.com)
  • Yes, all binoculars with the same magnification and objective diameter have the same exit pupil diameter. (birdforum.net)
  • Many companies exaggerate at this point and deliberately use off axis distortion magnification as a means to advertize blown "apparent" field sizes. (teleskop-express.de)
  • This means that one could see it at the edge of a distortionless 40° AFOV (w/AFOV=2ε) eyepiece at f /4, regardless of its focal length (consequence of the field stop size, for any given FOV angle, being inversely proportional to eyepiece magnification). (telescope-optics.net)
  • The pupil diameters on the X axis are arranged according to their squares (area). (co.ke)
  • Archives: In a study of 100 patients, researchers found that large pupils, contrary to conventional wisdom, had no effect on patient satisfaction or symptoms like halos and glare. (eyedocnews.com)
  • If optical aberrations in the eye could be eliminated, the theoretical limit of foveal acuity would be 20/12 for a small pupil and up to 20/5 for a dilated pupil. (medscape.com)
  • The optical aberration produced by each individual's eye is as distinct as each individual's fingerprints. (medscape.com)
  • Optical aberrations are classified into monochromatic and chromatic types. (medscape.com)
  • Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. (hindawi.com)
  • Some studies indicate that aberration-free aspheric IOLs may result in better optical quality compared to aberration-correcting aspheric IOLs-even in case of decentration and tilt of the IOL [ 8 ]. (hindawi.com)
  • No, small exit pupils work quite well in a good optical design that tolerates a bit of variation in alignment. (birdforum.net)
  • The LOE is thin and, as it expands, the optical exit pupil can work with a small image source. (medgadget.com)
  • Consequently, the LOE offers unprecedented compactness, breaking the conventional tradeoff between the optical performance and the physical size of a near-to-eye display. (medgadget.com)
  • High-performance glass elements, advanced optical design, and special anti-reflective coatings provide high-quality images that are aberration-free. (globalhutama.co.id)
  • 3. Pupil size - A larger than normal pupil size would exacerbate vision problems as it could require a larger optical zone for treatment. (laservue.com)
  • Phase-space distributions describe the effect of lens aberrations in real and angular frequency space simultaneously, enabling greater freedom in the design of optical elements. (spie.org)
  • Optical designers must reduce the effect of lens imperfection to improve resolution, and achieving this is costly, particularly for systems that require ultrahigh precision aberration suppression, such as lithographic projectors. (spie.org)
  • 8 Monochromatic Aberrations. (routledge.com)
  • The action of a perfect lens is to produce a spherical wave at the exit pupil under uniform illumination of monochromatic light. (spie.org)
  • To simplify our analysis, we shone a 1D uniform monochromatic wave of finite size onto the front surface of a 1D aberrated spherical lens, and examined the WDF at the back surface. (spie.org)
  • The larger size objective lenses facilitate the viewing in low light conditions as well as offers clear sharper images with a larger field of view. (globalhutama.co.id)
  • Dependences of negative lens forms from the position of anastigmatic pupils and from radii of meridional caustics which are convenient for understanding aberrational properties of anastigmatic lenses. (ifmo.ru)
  • With a 4.29mm exit pupil and 45mm objective lenses, the 10.5 x 45mm Endeavor ED is a bright binocular in twilight or low light situations. (astronomics.com)
  • Multifocal intraocular lenses (MIOLs) are not or only slightly affected by the pupil size and enable the elderly to meet their daily needs without depending on glasses and, thus, improve their quality-of-life after cataract surgery. (fortuneonline.org)
  • In contrast, this could not be shown in eyes with pupils under 4 mm or larger. (hindawi.com)
  • The analysis of variance within subjects applied to ARs introducing age and M S as covariates showed an increasing effect size of age from medium to large between ΔM of −0.5 and −2 D. In contrast, M S had a medium effect size (between ΔM of +2 and 0 D). (arvojournals.org)
  • In contrast, an OZ that was 9% smaller than the pupil (FC = 0.91) resulted in an HOA induction 50% higher than at FC = 1. (lasiksucks4u.com)
  • Outcome measures were better-eye monocular acuity, binocular acuity, better-eye contrast sensitivity, binocular contrast sensitivity, and pupil diameter under monocular and binocular conditions. (lasiksucks4u.com)
  • It's your mis-aligned eye's pupil intersection with the aberrated exit pupil of your telescope/eyepiece combination. (birdforum.net)
  • All three aberration are independent of mirror conic, which means that they are equally affecting both types of the Newtonian telescope, those with spherical and those with paraboloidal primary. (telescope-optics.net)
  • Fewer patients experience post-surgical visual aberrations. (seeclearly.com)
  • The aim of the present study was to determine the dynamic and static characteristics of the pupil in patients with DS and compare the results with those of normal subjects to assess whether dynamic and static pupillometric features are affected in DS. (oftalmoloji.org)
  • METHODS: Pupil measurements were taken of both eyes of 38 patients (76 eyes). (lasiksucks4u.com)
  • Thus, we recommend MIOLs that function independent of pupil size as appropriate for cataract surgeries in elderly patients. (fortuneonline.org)
  • In this study, we evaluated the pupil size and associated visual acuity before and after phacoemulsification in elderly patients with senile cataract. (fortuneonline.org)
  • Patients with tumors 2.5-3 cm in initial size went on to develop new or worsened symptoms 17% of the time. (medscape.com)
  • The exit pupil(s) of the binocular should be aligned with the pupils of your eyes in order for things to work right. (birdforum.net)
  • The Spearman correlation test was used to examine the correlation between the difference in spherical equivalent(SE) depending on pupil size and high order aberration. (online-koptometry.net)
  • Therefore, in order to increase satisfaction when wearing glasses, the spectacles prescription considering the high order aberration should be calculated. (online-koptometry.net)
  • We utilize the iTrace to show us the higher order aberrations present in a way that both the provider and patient can easily understand. (bauschsurgical.com)
  • The number of higher order aberrations can increase after PRK surgery , causing scarring of the retina. (healthhearty.com)
  • Higher-order aberrations are vision issues that regular eyeglasses cannot treat and require specialized diagnostic testing. (freshersnews.co.in)
  • In order to understand how, let's briefly review some basic information about the eye pupil and how it reacts to the amount of light in the environment. (nvadb.com)
  • 13 Higher Order Aberrations in Practice. (routledge.com)
  • The impact of the relationship between pupil diameter and OZ diameter (fractional clearance [FC]) on HOA was described and quantified using curvilinear regression with a 4th-order polynomial fit. (lasiksucks4u.com)
  • Previous studies have reported that the pupil size affects the higher order aberrations and, thus, has a great impact on the visual quality [3-5]. (fortuneonline.org)
  • 10 Finite or Total Aberrations from System Data by Ray Tracing. (routledge.com)
  • Sixty eyes requiring astigmatic correction from plano to -1.50DC were each evaluated at three pupil sizes (2.5 mm, 4 mm and 5.5 mm) using full sphero-cylindrical spectacle correction, full sphero-cylindrical correction with a custom toric soft contact lens, and best sphere correction using a spherical soft contact lens. (opticaljournal.com)
  • Recently, a theory has been proposed that the slit pupil aids predatory animals in seeing color in different light conditions. (koryoswrites.com)
  • 11 Hopkins' Canonical Coordinates and Variables in Aberration Theory. (routledge.com)
  • One commonly accepted theory is that aberrations can be evaluated in terms of Zernike polynomials (orthogonal circle polynomials). (spie.org)
  • Consequently, there have been great efforts to establish theories and methods to achieve such systems, 3 yet the aberration theory still needs further exploration. (spie.org)
  • In pupils with a minimum diameter of 4 mm spherical aberration had a significant effect on Strehl ratio, but not in pupils with a diameter less than 4 mm. (hindawi.com)
  • To minimize the diameter of the flap, the flap should be centered on the pupil, Dr. Devgan said. (ophthalmologytimes.com)
  • RESULTS: In mesopic luminance, the mean pupil diameter was 5.17 mm (range 3.0 to 7.5 mm) with the Bernell card method. (lasiksucks4u.com)
  • This coupled with the reduction in the average pupil size with age can produce a marked reduction in retinal illumination in the older driver. (co.ke)
  • Sensors smaller than "1-inch" size can support super zoom ranges, but at the cost of poor image quality, especially in dim light. (photoseek.com)
  • Muscles around the iris change the size of the pupil , regulating the amount of light that enters the eye [4] and reducing aberrations when there is enough light. (knowpia.com)
  • But the focus (ha ha) today is on the pupil, the transparent bit inside the iris that allows light to enter the eye. (koryoswrites.com)
  • Slit pupils allow the iris to contract or expand more dramatically- a human's round pupil can expand to allow light to be 10-fold more intense compared to its smallest size, while a cat's pupil expands to 135-fold intensity. (koryoswrites.com)
  • Any subject presenting with anterior segment disease, fixed or dilated pupils, iris abnormalities, or a history of eye disease or eye trauma was excluded. (lasiksucks4u.com)
  • Pupil measurement using the Colvard pupillometer. (lasiksucks4u.com)
  • PURPOSE: To compare scotopic pupil measurements obtained with a Colvard pupillometer with measurements taken with a printed pupil gauge and penlight with a cobalt blue filter attachment in mesopic and scotopic luminance. (lasiksucks4u.com)
  • At a scotopic luminance of less than 2.00 foot-candles, pupil measurements were taken with the Bernell card system and the Colvard pupillometer. (lasiksucks4u.com)
  • Its angular size needs to be ~5 arc minutes for its shape to be recognized by an average eye. (telescope-optics.net)
  • The standard method of centering the [flap made by the femtosecond laser] is first to dock and then center the reticle on the apparent center of the pupil using the mouse,' he said. (ophthalmologytimes.com)
  • The key point to remember is that if the pupil is centered perfectly, no clicks are required to correct the positioning of the flap,' Dr. Devgan said. (ophthalmologytimes.com)
  • The results clearly show a shear along the q axis due to the chirp, and the shear serves as the reference to evaluate the aberration. (spie.org)
  • Figures 6 and 7 show the effects of pupil size upon the light needed for the various visual targets. (co.ke)
  • We demonstrate that our proposed method leads to substantial performance improvements and facilitates the interactive exploration of visual aberrations when paired with our existing vision simulation algorithm. (unideb.hu)
  • In this paper, we present a new simulation method that supports arbitrary visual aberrations and runs at interactive, near real-time performance on commodity hardware. (unideb.hu)
  • The archaic inch -sizing of camera light sensors is clarified in the illustration and table below, with relative sizes and millimeters. (photoseek.com)
  • The need for more light with pupils below 3 millimeters is most evident. (co.ke)
  • High exit pupil provides clear bright images at low light conditions. (globalhutama.co.id)
  • In the light of the results of the present study, the pupil seems to be not involved in DS. (oftalmoloji.org)
  • By default, the human pupil changes size depending on the amount of light in the environment: when there is a lot of light, it contracts and becomes narrower, and when it's dark, it dilates to allow more light to get in. (nvadb.com)
  • Too small pupil sizes mean that too little light enters the eye, which impairs our ability to read or detect text, especially in low ambient light (for example, at night). (nvadb.com)
  • Slit pupils are found most often in animals with eyes that are exposed to highly variable light conditions- i.e., nocturnal or crepuscular animals. (koryoswrites.com)
  • In fish eyes, this detriment can be corrected by having a pupil with different focal lengths- i.e., different sharpness in the way light is angled towards the fovea. (koryoswrites.com)
  • Excuse my terrible paint art, but imagine that circle is the pupil and the lines are red and green light wavelengths. (koryoswrites.com)
  • Aberrations and scarring are present in the eyes of a normal person as well, but the extent of these aberrations is very less. (healthhearty.com)
  • The aberrometer measures alpha and beta so that it comes into focus at B, so basically by measurements of the alpha and beta, one can calculate the degree of aberrations across the pupil. (cybersight.org)
  • At a mesopic luminance of 2.11 foot-candles, pupil measurements were taken with a Bernell pupil card and penlight with a cobalt blue filter attachment. (lasiksucks4u.com)
  • As of 2018, 1-inch Type sensors optimize the size of a serious travel camera. (photoseek.com)
  • Many nocturnal species have round pupils which are actually quite good at contracting to very small sizes. (koryoswrites.com)
  • The Eurolens PUCS technology comprises a custom infrared imaging system with live image analysis software to monitor pupil size in real-time. (opticaljournal.com)
  • Buy a glass with a larger exit pupil. (birdforum.net)
  • If you click for a larger view you can just barely make out the slit pupils. (koryoswrites.com)
  • If the OZ was 16.5% larger than the pupil (FC = 1.17), only half the amount of HOA was expected to be induced than if the OZ equaled the pupil. (lasiksucks4u.com)