Lens Group Research Articles

Denied Victimhood and Contested Narratives: The Case of Hutu Diaspora

Based on 46 interviews conducted in a 2-month period, this article explored the identity narrative of three generations of the Hutu Diaspora community living in Belgium. Through a analysis of the Rwanda's National Identity policy and political categories, the research aimed to explore important themes such as sense of self and other, victimhood, and homeland through the lenses of the perpetrator group. Moreover, it was essential to investigate the trans-generational impact the perpetrator label has on the next generations. By looking at the Hutu population, the study was opening the door to the exploration of contested memories of survival for the perpetrator group. The complexity of the Hutu identity and their contested and competing narratives offered a fascinating approach to the study of mass atrocity as well as the field of conflict Resolution. This new generation of well educated, young Hutu has the power to shape the future of Rwanda in a very important way.

CONVEX LENS WITH TRANSPARENT GLASS SOLAR WATER HEATING SYSTEM

Conventional energy solutions are necessary in developing countries as current hot water production methods are becoming hazardous to the environment, economic development and the overall health and wealth of the population. The reason of this research paper is to create a convex lens with transparent glass solar water heater prototype, experimentally analyze the system and predict its characteristics when system exposed to the solar behavior of Bangalore, Karnataka, India. Present design from manufacturer and supplier is plane transparent glass solar water heating system. A user of solar energy minimum because cost of the product. With the merits of small structure, less weight, sharp focal length and minimum cost convex lenses are suitable for concentration of solar radiation and system improvement. The efficiency and optical property of transmitted solar radiation is improved and controlled compared to thick normal glass lenses and the solar radiation tracking accuracy need for convex lens group is less compared to other concentration methods.

Comparison of Rigid Gas Permeable and Toric Soft Lens for Correcting Astigmatism

Background: To compare visual acuity correction of astigmatism and comfort between toric softcontact lens and rigid gas permeable. Thus, ophthalmologists will less reluctantly propose contactlenses for the patients with astigmatism, and maximize the potential advantages of contact lenses forthe wearer.Methods: Literature review of all prospective and retrospective studies which reported managementof astigmatism with rigid gas permeable of toric soft contact lenses. The articles were divided intocharacteristics and outcomes. Outcomes reviewd were visual acuity, lens fit characteristics, cornealstaining, and subjective problems.Results: Lens corrected visual acuity by toric soft lens showed variation, which 3 studies reported afew amount of visual loss from spectacles corrected. Meanwhile other studies reported better toric softlens corrected visual acuity than spectacles. In RGP group, four studies reported better or the samevisual acuity with spectacles, and only one study showed a few amount of visual loss. Visual clarityand poor comfort were the most frequent subjective problems in toric soft lens group. Meanwhile,dryness and poor comfort were the most frequent subjective problems in RGP group.Conclusion: RGP is superior than toric soft lens in correcting astigmatism. Meanwhile, toric soft lensprovides quick adaptation and comfort. Keywords: astigmatism, rigid gas permeable, toric soft lens

Contact Lens Methods for Clinical Myopia Control.

A number of optical methods for slowing myopia progression have been tested and are now available. However, data on real-world use in clinical use is scarce. Here, we present a review of the clinical outcomes for patients attending a specialist myopia control clinic at The University of Auckland Optometry School, NZ. We report a comparative case series of 110 patients (aged 4-33 years, mean: 12.13 ± 4.58 years, 62% female) who attended the clinic between 2010 and 2014. Fifty-six were prescribed orthokeratology, 32 dual focus soft contact lenses, and 22 received advice only. Initial myopia, vitreous and axial eye length, previous myopia progression, age, number of myopic parents, and gender were not significantly different between orthokeratology and dual focus soft contact lens groups. Mean follow-up time for the orthokeratology and dual focus lens groups was the same (orthokeratology: 1.30 ± 0.88 years; dual focus lens: 1.33 ± 0.80 years (p = 0.989)). There was a significant reduction in the annualized myopia progression in both groups (orthokeratology: -1.17 ± 0.55 to -0.09 ± 017 D/yr, p < 0.001; dual focus soft contact lens: -1.15 ± 0.46 to -0.10 ± 0.23 D/yr, p < 0.001). There was no difference between orthokeratology and dual focus lens treatment efficacy (p = 0.763), nor in axial or vitreous chamber length changes after treatment (p = 0.184). One adverse event was reported over the 4-year period. Both orthokeratology and dual focus soft contact lenses are effective strategies for targeting myopia progression in the clinic. We saw no significant difference in the efficacy of the two methods in this regard, and so we believe there are very few barriers for any contact lens practitioner to be actively promoting myopia control treatment to at-risk patients.

Bidirectional Expression of Metabolic, Structural, and Immune Pathways in Early Myopia and Hyperopia.

Myopia (short-sightedness) affects 1.45 billion people worldwide, many of whom will develop sight-threatening secondary disorders. Myopic eyes are characterized by excessive size while hyperopic (long-sighted) eyes are typically small. The biological and genetic mechanisms underpinning the retina's local control of these growth patterns remain unclear. In the present study, we used RNA sequencing to examine gene expression in the retina/RPE/choroid across 3 days of optically-induced myopia and hyperopia induction in chick. Data were analyzed for differential expression of single genes, and Gene Set Enrichment Analysis (GSEA) was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we found few single genes that were differentially-expressed in a sign-of-defocus dependent manner (only BMP2 at 1 day). Using GSEA, however, we are the first to show that more subtle shifts in structural, metabolic, and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological stress arising from metabolic and inflammatory pathway activation could increase the vulnerability of myopic eyes to secondary pathologies.

A high speed compact microwave interferometer for density fluctuation measurements in Sino-UNIted Spherical Tokamak.

A single-channel 3 mm interferometer has been developed for plasma density diagnostics in the Sino-UNIted Spherical Tokamak (SUNIST). The extremely compact microwave interferometer utilizes one corrugated feed horn antenna for both emitting and receiving the microwave. The beam path lies on the equatorial plane so the system would not suffer from beam path deflection problems due to the symmetry of the cross section. A focusing lens group and an oblique vacuum window are carefully designed to boost the signal to noise ratio, which allows this system to show good performance even with the small-diameter central column itself as a reflector, without a concave mirror. The whole system discards the reference leg for maximum compactness, which is particularly suitable for the small-sized tokamak. An auto-correcting algorithm is developed to calculate the phase evolution, and the result displays good phase stability of the whole system. The intermediate frequency is adjustable and can reach its full potential of 2 MHz for best temporal resolution. Multiple measurements during ohmic discharges proved the interferometer's capability to track typical density fluctuations in SUNIST, which enables this system to be utilized in the study of MHD activities.

The Effects of the Relative Strength of Simultaneous Competing Defocus Signals on Emmetropization in Infant Rhesus Monkeys.

PurposeWe investigated how the relative surface area devoted to the more positive-powered component in dual-focus lenses influences emmetropization in rhesus monkeys.MethodsFrom 3 to 21 weeks of age, macaques were reared with binocular dual-focus spectacles. The treatment lenses had central 2-mm zones of zero-power and concentric annular zones that had alternating powers of either +3.0 diopters (D) and 0 D (+3 D/pL) or −3.0 D and 0 D (−3 D/pL). The relative widths of the powered and plano zones varied from 50:50 to 18:82 between treatment groups. Refractive status, corneal curvature, and axial dimensions were assessed biweekly throughout the lens-rearing period. Comparison data were obtained from monkeys reared with binocular full-field single-vision lenses (FF+3D, n = 6; FF−3D, n = 10) and from 35 normal controls.ResultsThe median refractive errors for all of the +3 D/pL lens groups were similar to that for the FF+3D group (+4.63 D versus +4.31 D to +5.25 D; P = 0.18–0.96), but significantly more hyperopic than that for controls (+2.44 D; P = 0.0002–0.003). In the −3 D/pL monkeys, refractive development was dominated by the zero-powered portions of the treatment lenses; the −3 D/pL animals (+2.94 D to +3.13 D) were more hyperopic than the FF−3D monkeys (−0.78 D; P = 0.004–0.006), but similar to controls (+2.44 D; P = 0.14–0.22).ConclusionsThe results demonstrate that even when the more positive-powered zones make up only one-fifth of a dual-focus lens' surface area, refractive development is still dominated by relative myopic defocus. Overall, the results emphasize that myopic defocus distributed across the visual field evokes strong signals to slow eye growth in primates.

Effects of orthokeratology on the progression of low to moderate myopia in Chinese children.

BackgroundTo investigate the effectiveness of orthokeratology (ortho-k) in reducing the development of myopia in Chinese children with low to moderate myopia.MethodsThis was a retrospective study. In the ortho-k group, there were141 subjects, and the average age was (9.43 ± 1.10) years. The average spherical equivalent refractive error (SER) was (−2.74 ± 1.15)D, with examinations performed 1, 7, 30, and 90 days and 12 months after the patients started wearing ortho-k lenses. In the control group, there were 130 subjects, and the average age was (9.37 ± 1.00) years. The average SER was (−2.88 ± 1.39)D, with examinations performed every 6 months. Axial elongation, which is an important parameter reflecting the progression of myopia, was measured at baseline from the same IOLMaster each time by the same masked examiner and was compared between the groups after 1 year. The subjects were divided into two sub-groups according to age to further study the development of myopia at different ages. An unpaired t-test, paired t-test, Chi-square test and Spearman test were performed to analyze the data.ResultsAfter 1 year, the average axial elongation was (0.27 ± 0.17) mm in the ortho-k lens group and (0.38 ± 0.13) mm in the control group, with a significant difference between the groups (P < 0.001). Axial elongation was not correlated with SER but had a negative correlation with initial age (ortho-k group: rs = −0.309, p < 0.01; control group: rs = −0.472, p < 0.01). The percentages of individuals with fast myopic progression (axial elongation > 0.36 mm per year) were 38.0 % among younger children (7.00 to 9.40 years) and 24.3 % among older children (9.40 to 12.00 years), whereas the respective percentages were 76.5 and 12.9 % in the control group. When SER ranged from -5.0D to −6.0D, the axial elongation in the ortho-k group was 57.1 % slower than that in the control group.ConclusionsOrtho-k lenses are effective in controlling myopic progression in Chinese children, particularly in younger children and in children with higher myopia.

Application effect of continuity care in uveitis complicated cataract patients after phacoemulsification with intraocular lens

Objective To observe the clinical effects of continuity care in uveitis complicated cataract patients after phacoemulsification with intraocular lens. Methods From March 2011 to October 2014, 107 cases (150 eyes) uveitis complicated cataract patients after phacoemulsification with intraocular lens were in the study. All cases were divided into two groups randomly. Continuity care were used in observation group (54 cases, 80 eyes) after phacoemulsification with intraocular lens and control group (53 cases, 70 eyes) accepted routine nursing. After discharging for 1 month, the dates including vision, change of pupil, complication and cured rate were collected by assigned person, compared and analyzed. Results Vision in two groups all improved after treatment, and dates in observation group were better than control group (P<0.05). All pupil were normal and the diameter were 2-4 mm. Complication rate in control group was higher than observation group (11.43% vs 0.00%), cured rate was opposite (87.14% vs 96.25%). The compliance behavior rates of the control group and observation group were 60.0%, 93.8%, the difference was statistically significant (P<0.05). The care satisfaction of the control group and the observation group were 71.4%, 98.8%, the difference was statistically significant (P<0.05). Conclusions Continuity care shows a significant effect in promoting prognosis in uveitis complicated cataract patients after phacoemulsification with intraocular lens. Key words: Continuity care; Uveitis; Cataract; Phacoemulsification with intraocular lens

Mullers Muscle Conjunctival Resection for Treatment of Contact Lens-Associated Ptosis.

The aim of this study was to look at the surgical outcomes of posterior approach Mullers muscle conjunctival resection surgery for contact lens-related ptosis. This was a retrospective, comparative interventional case series. All patients and controls underwent phenylephrine 10% testing and had a positive response prior to surgical intervention. Thirty-one eyelids with ptosis were identified in 20 contact lens wearing patients, which were matched with 27 eyelids in 15 controls. The contact lens wearing patients wore contact lenses for a mean of 20.6 ± 12.1 years. More than half (60%) wore soft contact lenses, as opposed to rigid gas-permeable contact lenses. Preoperative margin-to-reflex distance-1 was lower in patients who wore rigid contact lenses (0.8 ± 0.7 mm) as compared with patients with soft contact lenses (1.7 ± 1.1 mm) (p = 0.01). Surgical success, as defined by margin-to-reflex distance-1 ≥3 mm or symmetry of upper eyelid height (within 1 mm), was achieved in 93.5% in the contact lens group and 92.6% of controls. Postoperative margin-to-reflex distance-1 was significantly higher in the contact lens wearers (3.9 ± 1.3 mm) compared with the controls (3.2 ± 1.1 mm; p = 0.01). There was a significant correlation between the amount of tissue resected intraoperatively and the improvement in margin-to-reflex distance-1 (Pearsons correlation coefficient, r =0.36; p = 0.006). There were no surgical complications of any patients in the study. Mullers muscle conjunctival resection surgery is an effective surgical correction for contact lens-associated ptosis. Patients can achieve excellent results with minimal risk of residual ptosis or asymmetry.

Association between multifocal soft contact lens decentration and visual performance.

PurposeThe aim of this study was to assess the association between decentration of several commercial multifocal soft contact lenses (MFCLs) and various objective and subjective visual performance variables in presbyopic and non-presbyopic participants.Materials and methodsAll presbyopic (age >40 years, near add ≥+1.25 D) and non-presbyopic (age ≥18 years, no near add requirements, spherical equivalent ≤−0.50 D) participants were each fitted bilaterally with six and two MFCLs (test lens), respectively, and with one single vision lens (control lens). Lens decentration, ie, the x- and y-differences between the contact lens and pupil centers, was objectively determined. Third-order aberrations were measured and compared. Visual performance (high- and low-contrast acuities and several subjective variables) was analyzed for any associations (Pearson’s correlation, r) with MFCL decentration.ResultsA total of 17 presbyopic (55.1±6.9 years) and eight non-presbyopic (31.0±3.3 years) participants completed the study. All lenses displayed a temporal–inferior decentration (x=−0.36±0.29 mm, y=−0.28±0.28 mm, mean ± SD). Compared to the control, a significant inferior decentration was found for the Proclear® MFCL Near lens in both groups (ypresbyopic =−0.26 mm, ynon-presbyopic =−0.70 mm) and for the Proclear® MFCL Distance lens in the non-presbyopic group (ynon-presbyopic =−0.69 mm). In both groups, lens-induced vertical coma (C(3, −1)) was, by at least tenfold, significantly more positive for the Proclear® MFCL Distance lens and significantly more negative for the Proclear® MFCL Near lens. In the presbyopic group, the correlation of total MFCL decentration with vision variables was weak (r<|0.191|). Conversely, a moderate but significant correlation with total MFCL decentration was found in the non-presbyopic group for most of the vision variables, indicating a decrease in vision as decentration increased.ConclusionCertain MFCLs decentered more than others; the same lens designs also induced significant amounts of third-order aberrations. An association between MFCL decentration and seven out of nine vision variables was found in the non-presbyopic group, ie, the group where lenses were most decentered, which had larger pupils and lower levels of inherent third-order aberrations.

A prospective comparison of phakic collamer lenses and wavefront-optimized laser-assisted in situ keratomileusis for correction of myopia.

PurposeThe aim of this study was to evaluate and compare night vision and low-luminance contrast sensitivity (CS) in patients undergoing implantation of phakic collamer lenses or wavefront-optimized laser-assisted in situ keratomileusis (LASIK).Patients and methodsThis is a nonrandomized, prospective study, in which 48 military personnel were recruited. Rabin Super Vision Test was used to compare the visual acuity and CS of Visian implantable collamer lens (ICL) and LASIK groups under normal and low light conditions, using a filter for simulated vision through night vision goggles.ResultsPreoperative mean spherical equivalent was −6.10 D in the ICL group and −6.04 D in the LASIK group (P=0.863). Three months postoperatively, super vision acuity (SVa), super vision acuity with (low-luminance) goggles (SVaG), super vision contrast (SVc), and super vision contrast with (low luminance) goggles (SVcG) significantly improved in the ICL and LASIK groups (P<0.001). Mean improvement in SVaG at 3 months postoperatively was statistically significantly greater in the ICL group than in the LASIK group (mean change [logarithm of the minimum angle of resolution, LogMAR]: ICL =−0.134, LASIK =−0.085; P=0.032). Mean improvements in SVc and SVcG were also statistically significantly greater in the ICL group than in the LASIK group (SVc mean change [logarithm of the CS, LogCS]: ICL =0.356, LASIK =0.209; P=0.018 and SVcG mean change [LogCS]: ICL =0.390, LASIK =0.259; P=0.024). Mean improvement in SVa at 3 months was comparable in both groups (P=0.154).ConclusionSimulated night vision improved with both ICL implantation and wavefront-optimized LASIK, but improvements were significantly greater with ICLs. These differences may be important in a military setting and may also affect satisfaction with civilian vision correction.

Mining unstructured content for recommender systems: an ensemble approach

Recommendation of textual documents requires indexing mechanisms to extract structured metadata for attribute-aware recommender systems. Applying a variety of text mining algorithms has the advantage of capturing different aspects of unstructured content, resulting in richer descriptions. However, it is difficult to integrate them into a unique model so that these descriptions can efficiently improve recommendation accuracy. This article proposes a generic model based on ensemble learning that combines simple text mining methods in a post-processing approach. After executing each text mining technique, each set of metadata of a particular type is applied to the recommender module, which generates attribute-specific rankings. Then, the resulting recommendations are ensembled to generate a final personalized ranking to the user. We evaluated our ensemble technique with two attribute-aware collaborative recommenders (k-Nearest Neighbors and BPR-Mapping) and we demonstrate its generality by means of comparisons among different types of ensembles. We used two datasets from different domains, the first is from the Brazilian Embrapa Agency of Technology Information website, whose documents are written in Portuguese language, and the second is the HetRec MovieLens 2k, published by the GroupLens Research Group, whose movies' storylines are written in English. The experiments show that, particularly to the k-NN recommender, better accuracy can be obtained when multiple metadata types are combined. The proposed approach is extensible and flexible to new indexing and recommendation techniques.

Regional groundwater flow and geochemical evolution in the Amacuzac River Basin, Mexico

An approach is presented to investigate the regional evolution of groundwater in the basin of the Amacuzac River in Central Mexico. The approach is based on groundwater flow cross-sectional modeling in combination with major ion chemistry and geochemical modeling, complemented with principal component and cluster analyses. The hydrogeologic units composing the basin, which combine aquifers and aquitards both in granular, fractured and karstic rocks, were represented in sections parallel to the regional groundwater flow. Steady-state cross-section numerical simulations aided in the conceptualization of the groundwater flow system through the basin and permitted estimation of bulk hydraulic conductivity values, recharge rates and residence times. Forty-five water locations (springs, groundwater wells and rivers) were sampled throughout the basin for chemical analysis of major ions. The modeled gravity-driven groundwater flow system satisfactorily reproduced field observations, whereas the main geochemical processes of groundwater in the basin are associated to the order and reactions in which the igneous and sedimentary rocks are encountered along the groundwater flow. Recharge water in the volcanic and volcano-sedimentary aquifers increases the concentration of HCO3 –, Mg2+ and Ca2+ from dissolution of plagioclase and olivine. Deeper groundwater flow encounters carbonate rocks, under closed CO2 conditions, and dissolves calcite and dolomite. When groundwater encounters gypsum lenses in the shallow Balsas Group or the deeper Huitzuco anhydrite, gypsum dissolution produces proportional increased concentration of Ca2+ and SO4 2–; two samples reflected the influence of hydrothermal fluids and probably halite dissolution. These geochemical trends are consistent with the principal component and cluster analyses.

Design of an 8x Four-group Inner-focus Zoom System Using a Focus Tunable Lens

This study presents an 8x four-group inner-focus zoom lens with one-moving group for a compact camera by use of a focus tunable lens (FTL). In the initial design stage, we obtained the powers of lens groups by paraxial design based on thin lens theory, and then set up the zoom system composed of four lens modules. Instead of numerically analytic analysis for the zoom locus, we suggest simple analysis for that using lens modules optimized. After replacing four groups with equivalent thick lens modules, the power of the fourth group, which includes a focus tunable lens, is designed to be changed to fix the image plane at all positions. From this design process, we can realize an 8x four-group zoom system having one moving group by employing a focus tunable lens. The final designed zoom lens has focal lengths of 4 mm to 32 mm and apertures of F/3.5 to F/4.5 at wide and tele positions, respectively.

Comparison of visual outcomes after implantation of diffractive trifocal toric intraocular lens and a diffractive apodized bifocal toric intraocular lens.

PurposeThe aim of this study was to compare a new diffractive trifocal toric lens with an apodized diffractive bifocal toric lens in terms of refractive and visual acuity (VA) outcomes, including low-contrast VA (LCVA), as well as the patient’s visual function 3 months after implantation.Patients and methodsThis is a randomized prospective study involving bilateral implantation of a trifocal toric or a bifocal toric lens. At 3 months postoperatively, the subject’s vision was tested both uncorrected and with his/her best distance correction at: distance (4 m), intermediate (63 cm), and near (40 cm). Binocular defocus curves were measured with no correction and with the subject’s best distance correction in place. Quality of vision was measured using the National Eye Institute Visual Function Questionnaire.ResultsA total of 22 patients were enrolled (eleven in each group). There was no statistically significant difference in the absolute change in measured rotation between 1 month and 3 months postoperatively between the two intraocular lens (IOL) groups (P=0.98). At 3 months, the postoperative refraction and distance VA by eye were similar between groups. There was no statistically significant difference in the measured LCVA between groups (P=0.39). The defocus curve showed that at 67 cm, the trifocal toric lens had statistically significantly better VA when compared to the bifocal toric lens. There were no statistically significant differences by group for any of the National Eye Institute Visual Function Questionnaire scores (P>0.26 in all cases).ConclusionThe trifocal toric IOL improved the intermediate vision without negatively impacting visual function and distance, near, or low-contrast VA when compared to a bifocal toric IOL. The toric component of the trifocal lens effectively reduced astigmatism and provided good rotational stability.

Analysis of the Optical Quality of Spherical and Aspheric Intraocular Lenses in Simulated Nanophthalmic Eyes.

To analyze the optical performance of different implant strategies in simulated nanophthalmic eyes. An optical design software was used. Analysis included eye models that required 30.00, 45.00, and 60.00 diopters (D) intraocular lenses (IOLs) to achieve emmetropia. Spherical and aspheric IOLs were designed. They were tested either with a single implant setting S or by splitting the power into two lenses. Setting P1 had an even split of the power between the lenses and setting P2 had an uneven power split with one-third of the power in the anterior lens and two-thirds in the posterior IOL. The area under the modulation transfer function (MTF) curve was calculated and spherical aberration was recorded in each setting. Setting S had the worst optical performance in the spherical group and the best performance in the aspheric group. A statistically significant difference was found between setting S and the piggyback options (settings P1 and P2) in all analyzed variables for the spherical and aspheric groups for the 45.00 and 60.00 D IOL requirement. No statistically significant difference was found between the piggyback settings. Single aspheric IOLs had better optical performance than piggybacking lower-power aspheric IOLs. In the spherical lenses group, the results were the opposite, with the piggyback options having higher optical quality than the single IOL. MTF shows that single aspheric lenses provide the highest contrast sensitivity among all of the analyzed settings.

Non-blind area PAL system design based on dichroic filter.

An inevitable problem of Panoramic Annular Lens (PAL) System is the blind area in the central part of image plane, which vastly reduces the pixel efficiency of detector. Here we present a design of PAL system based on dichroic filter, which can combine two channels of rays in different bands and image them on the same detector. The dichroic filter in this paper is designed to make ultraviolet rays reflect and visible rays transmit, and the ultraviolet rays are imaged on the PAL imaging area while the visible rays are imaged on the blind area of conventional PAL image plane. In order to image both bands of rays on the same plane, we add a correcting lens group in front of PAL system. As a result, the FOV of ultraviolet channel is ranging from 30°~90° and the one of visible channel is ranging from 0°~10°.

Objective and subjective evaluation of the performance of medical contact lenses fitted using a contact lens selection algorithm.

To evaluate the performance of medical contact lenses (CLs) for a wide range of clinical indications. Prospective cross-sectional study. A total of 281 eyes were evaluated in 281 consecutive patients (≥18 years of age; CL use ≥3 months) who visited the contact lens service in a tertiary academic clinic for a scheduled follow-up visit. The main outcome measured were clinical indications for CL wear; CL type; change in corrected distance visual acuity (CDVA) with CL use; CL wearing duration; CL wearing time; subjective performance measured using a visual analog scale (VAS) questionnaire (score range: 0-100); and effectiveness of the lens-selection algorithm. Wearing CLs significantly improved CDVA compared to wearing spectacles (median change: -0.15 logMAR, range: 1.00 to -2.10; P<.001). Daily-wear CLs were worn by 77% of patients for a median of 15h/day (range: 5-18h/day), median 7 days/week (range: 1-7 days/week). High subjective scores were measured, with similar results obtained between the scleral lens and soft lens groups. The medical CL fitting was found to be generally effective (the overall satisfaction rating was ≥70 for 81% of patients). Fitting CLs based on the lens-selection algorithm yielded positive clinical results, including improved visual acuity, satisfactory wearing time, and high overall subjective performance. Moreover, subjective performance was similar between users of scleral lenses and users of soft lenses. These results underscore the importance of prescribing scleral lenses and the need for tertiary eye clinics to offer patients a variety of CL types.

Analytical model for effect of temperature variation on PSF consistency in wavefront coding infrared imaging system

The point spread function (PSF) inconsistency caused by temperature variation leads to artifacts in decoded images of a wavefront coding infrared imaging system. Therefore, this paper proposes an analytical model for the effect of temperature variation on the PSF consistency. In the proposed model, a formula for the thermal deformation of an optical phase mask is derived. This formula indicates that a cubic optical phase mask (CPM) is still cubic after thermal deformation. A proposed equivalent cubic phase mask (E-CPM) is a virtual and room-temperature lens which characterizes the optical effect of temperature variation on the CPM. Additionally, a calculating method for PSF consistency after temperature variation is presented. Numerical simulation illustrates the validity of the proposed model and some significant conclusions are drawn. Given the form parameter, the PSF consistency achieved by a Ge-material CPM is better than the PSF consistency by a ZnSe-material CPM. The effect of the optical phase mask on PSF inconsistency is much slighter than that of the auxiliary lens group. A large form parameter of the CPM will introduce large defocus-insensitive aberrations, which improves the PSF consistency but degrades the room-temperature MTF.