个性超声乳化切口并不同类型人工晶状体植入术后角膜散光和视觉质量的比较

目的 比较常规上方透明角膜切口与角膜地形图引导切口并植入不同类型人工晶状体(IOL)的白内障合并角膜散光患者术后角膜散光、波前像差的差异.方法 采用前瞻性随机对照临床研究方法.对术前存在角膜散光的年龄相关性白内障患者90例(90只眼),采用分段随机分组法分为3组:常规上方透明角膜切口超声乳化白内障吸除联合AcrySof SN60AT IOL植入组(A组),角膜地形图引导切口超声乳化白内障吸除联合AcrySof SN60AT IOL植入组(B组),角膜地形图引导切口超声乳化白内障吸除联合AcrySof SN60WF IOL植入组(C组),术后1周、1个月、3个月及6个月复查角膜地形图,术后3个月使用以Tscheming原理建立的波前像差分析仪测量3组患者术后IOL眼的像差,并在瞳孔直径为6 mm条件下比较3、4、5、6阶像差,总体高阶像差,总体像差及球差、彗差的均方根(RMS)值.统计学分析方法采用重复测茸资料方差分析、卡方检验、单因素方差分析及SNK法两两比较.结果 角膜地形图检查显示术前各组散光值差异无统计学意义(F=0.08,P>0.05),3组患者角膜散光经矢量分解为J0,J45和P,经重复测量资料方差分析,对于反映垂直和水平方向散光的J0和矢量长度的P,A组与B、C组比较差异有统计学意义(F=9.54,18.69;均P<0.01),而B、C组比较无统计学意义(P>0.05),处理组与时间有交互效应(F=13.45,50.22;均P<0.01),3组患者手术前后不同时间的散光值差异有统计学意义(F=74.33,92.11;均P<0.01);术后3个月波前像差检查显示,A组总体像差(RMSg)、彗差、高阶像差(RMSh)、3阶像差(RMS3)及5～6阶像差显著高于B组及C组(F=93.40,471.94,176.95,216.99,44.37,37.19;均P<0.01),而且A组RMS4及球差显著高于C组(q=25.30,26.23;均P<0.01),但RMS4及球差与B组比较差异无统计学意义(q=0.57,2.34;均P>0.05),B组RMS4,RMSh,RMSg及球差显著高于C组(q=24.73,7.90,6.41,23.89;均P<0.01).结论 对于合并角膜散光的白内障患者,角膜地形图引导超声乳化切口联合负球面像差IOL植入可以矫正术前的角膜散光,减少IOL眼的球差、高阶像差及总像差,从而提高患者的视觉质量.     

术前配戴软性角膜接触镜对LASIK术后高阶像差的影响

目的探讨术前配戴软性角膜接触镜对波前引导和传统准分子激光原位角膜磨镶术(LASIK)术后高阶像差的影响。方法采用前瞻性随机双盲比较性研究,将拟行LASIK的青壮年近视患者48名(96眼),其中,术前配戴软性角膜接触镜者26名(52眼),随机分为波前引导组和传统组,分别检查术前、术后不同时间的视力、对比敏感度和高阶像差,并比较术前戴角膜接触镜组(contactlens,C组)与未戴组(non-contactlens,N组)术后高阶像差变化。结果无论是传统组还是波前引导组术后不同时间的裸眼视力(UCVA)、最佳矫正视力(BSCVA)、安全指数、有效指数和对比敏感度增加倍率等方面C组与N组均无显著差异(P>0.05)。传统组和波前引导组术后总高阶像差和各高阶像差RMS值(RMSh和RMS3～6值)均较术前增加,平均增加约1倍。传统组中术后RMSh和RMS3～6值增加倍率和下降比例C组与N组无显著差异,术后6个月时RMSh值增加倍率分别为1.28倍、1.17倍。引导组中术后RMSh、RMS3～5值增加倍率C组均明显高于N组(P<0.05),术后6个月时RMSh值增加倍率分别为1.58倍、0.77倍(P<0.05),N组术后不同时间RMSh、RMS3～5值下降比例均高于C组。术后6个月时,RMSh值下降比例C组与N组分别为9.1%和22.7%。结论术前配戴软性角膜接触镜影响波前引导LASIK对高阶像差的矫正,而对传统LASIK术后高阶像差影响不明显。术前配戴软性角膜接触镜者行波前引导LASIK应慎重。     

准分子激光原位角膜磨镶术术中一眼激光切削延迟时双眼波阵面像差的分析

目的利用波阵面像差检测仪探讨准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)中角膜瓣制作与激光扫描切削在时间上有延迟时对手术效果的影响。方法30例(60眼)近视患者自愿接受LASIK手术。手术方式基本同常规LASIK术,不同点为:用角膜刀先后制作左、右眼带蒂上方角膜瓣,再分别对右、左眼角膜基质层行激光切削。于术前、术后第1周、第1个月、第3个月进行双眼波阵面像差的检测和分析。结果术前双眼波阵面像差均方根值(root means squares,RMS)检测各组值比较差异无显著性(P>0.05)。术后第1周在中小瞳孔直径下,右、左眼RMS2和RMSg比较差异有显著性(P<0.05)。术后第1个月仅在小瞳孔直径下,右、左眼RMS2比较差异有显著性(P<0.05)。RMS1、RMS3-6、RMSg及RMSh各组值比较差异均无显著性(P>0.05)。术后第3个月双眼RMS各组值比较差异均无显著性(P>0.05)。术后各时期双眼裸眼视力、最佳矫正视力、平均屈光度比较差异均无显著性(P>0.05)。结论该手术方式步骤衔接紧密,省出有效时间消毒显微角膜板层刀和相关器械,对术后稳定效果无影响,适宜于对大批患者集中进行手术,易于推广应用。     

人工泪液对干眼症患者眼像差及角膜地形图的影响

目的 观察干眼症患者滴用人工泪液后眼像差和角膜地形图的改变.方法 对18例(30只眼)干眼症患者滴用人工泪液前、用药后即刻和用药10min后进行眼像差和角膜地形图的测量,分析指标为像差均方根值(RMSg),垂直慧差(C7),水平慧差(C8),球差(C12),角膜表面规则性指数(SRI)和角膜表面不对称指数(SAI),采用重复测量方差分析方法 对数据进行分析,以P<0.05认为差异具有统计学意义.结果用药后即刻测得的RMSg、C7、C8、C12、SRI和SAI值较用药前明显下降(P≤0.01),指标在用药10min时仍然维持稳定.结论 人工泪液可以改变干眼症患者角膜表面的不规则性参数,从而通过改变RMSg、C7、C8、C12、SRI和SAI值来改善其光学视觉质量.     

圆锥角膜配戴硬性透气性角膜接触镜后角膜表面形态的改变

目的 评价圆锥角膜患者配戴硬性透气性角膜接触镜(RGP)后角膜前表面非球面形态(Q值)的改变以及SimK值的改变。方法 收集山西省眼科医院就诊的圆锥角膜患者25人43只眼,选配合适的RGP,分别于配戴前及配戴后1个月、3个月、6个月、12个月测定其矫正视力,并进行OPD-scan角膜地形图检查,采集角膜中央散光值、SimK值、Q值等参数,分析Q值及SimK值随配戴时间的变化,SimK值改变与角膜Q值改变有无相关性。结果 患者配戴RGP前,角膜散光值、Simk值、Q值分别为-6.03±2.66、50.12±5.65、-2.29±1.17。配戴RGP 3个月后角膜散光值、Simk值、Q值分别为-4.07±1.97、49.47±5.55、-1.62±0.95。角膜散光值、Simk值、Q值在配戴RGP前后差异有统计学意义。SimK值改变与角膜Q值改变有着显著的相关性,相关系数为0.698。配戴3个月、6个月及12个月后,角膜散光值,Simk值,Q值差异无统计学意义。结论 RGP为圆锥角膜患者提供了良好的视力矫正,并且可以在一定程度上改变角膜前表面的形态,从而控制圆锥角膜病情的发展。这种改变在配戴后3个月较为明显。随着配戴时间的延长,角膜散光值,Simk值,Q值趋于稳定。     

远视儿童高阶像差的研究

目的探讨远视儿童的高阶像差分布、影响因素及对视功能的影响。设计临床病例系列。研究对象44例(81眼)3￣13岁等效球镜 0.50￣ 6.63D远视儿童。方法使用Allegretto波阵面像差仪对上述远视儿童进行波阵面像差测量分析。主要指标高阶像差及其分布,高阶主导像差、高阶像差与瞳孔大小、性别和屈光状态的关系,高阶像差与戴镜矫正视力的关系。结果在6.5mm和4.0mm瞳孔直径时,总高阶像差、3阶和4阶像差均方根值(RMSh、RMS3、RMS4)分别为(0.20±0.05)、(0.15±0.06)、(0.10±0.02)μm和(0.09±0.03)、(0.07±0.03)、(0.05±0.02)μm,差异均有统计学意义(P<0.05),RMSh值呈正态分布;高阶像差均以3阶像差所占比例最高,均占80.2%,主导像差以C7为最高。瞳孔从4.0mm增大到6.5mm,RMSh、RMS3、RMS4分别增加1.36、1.42、1.45倍。不同类型的高阶主导像差对戴镜矫正视力无影响(P>0.05)。RMSh值与戴镜矫正视力无相关性(P>0.05)。性别、球镜、柱镜对RMSh无显著影响(P>0.05)。结论远视儿童高阶像差分布范围宽,部分患儿RMSh值较高;高阶像差各阶及RMSh值随瞳孔增大而增加;远视患儿中高阶主导像差以垂直彗差居多;瞳孔增大时球差、彗差比率增加。(眼科,2006,15:187-190)     

准分子激光角膜表层手术与基质层手术对眼波前像差的比较

目的:比较分析角膜表层与基质层屈光手术后高阶像差及其变化值。方法:行准分子激光治疗的近视眼患者100例200眼,其中接受LASIK手术50例100眼,接受新型表层手术(ASA)50例100眼。LASIK手术组术前等效球镜度(SE)为-1.25～-9.25(平均-5.75±1.74)D,ASA手术组术前SE为-2～-9.25(平均-5.42±1.81)D。术前及术后1,3,6mo检查裸眼视力(UCVA)、最佳矫正视力(BSCVA)、球镜及柱镜度数、SE以及波前像差等。结果:C7,C12,RMS3,RMS4,RMS5,RMS6和RMSh的变化值均和球镜度变化值、SE变化值的绝对值显著正相关。术后1mo,ASA组C7绝对值、RMSh,RMS3和RMS6均显著小于LASIK组;术后3mo时,ASA组C7和C14显著小于LASIK组,LASIK组C12显著小于ASA组;术后6mo时,ASA组仅C14显著优于LASIK组。术后1mo时,ASA组RMS3,RMS5,RMS6和RMSh的变化值均显著小于LASIK组,术后3mo时,ASA组RMS6变化值显著小于LASIK组,术后6mo时,ASA组RMS3,RMS6和RMSh的变化值显著小于LASIK组。结论:高阶像差增大程度与球镜度及SE的变化程度正相关。ASA组术后高阶像差及其增大程度均小于LASIK组,术后6mo时两组差异仍显著。     

LASIK手术前后屈光状态和角膜形态对高阶像差的影响

目的 分析近视散光患者行准分子激光原位角膜磨镶术(LASIK)手术前后屈光状态和角膜形态对高阶像差的影响.方法 在LASIK术前和术后6个月,分别对患者69例108眼进行角膜地形图和波前像差检查,屈光矫正范围(-1.25～-9.00)D,切削直径为6.0 mm或6.5 mm.结果 LASIK手术前后在6.0 mm瞳孔直径下最主要的高阶像差是3阶彗差、4阶球差和三叶草散光,术后总高阶像差的均方根(RMSh)增加1.82倍.术后RMSh变化与近视度的矫正量呈正相关,主要表现为3阶彗差和4阶球差的变化.术后角膜表面不对称指数(SAI)显著增加,RMSh的变化与其增加量呈正相关,特别是3阶彗差.角膜形态术前为不规则型及术后为半环型和中央岛型时SAI增大,高阶像差增大.结论 LASIK手术前后的主要高阶像差均为3阶彗差和4阶球差.术后总高阶像差增大,主要表现为慧差增大,可能为角膜表面的不对称性增大引起.     

超薄角膜瓣LASIK与LASEK治疗角膜相对较薄高度近视眼的角膜地形图和波前像差的对比研究

目的 对超薄角膜瓣准分子激光原位角膜磨镶术(LASIK)和准分子激光上皮下角膜磨镶术(LASEK)治疗角膜相对较薄的高度近视眼术后的角膜地形图和波前像差进行比较,探讨其与视觉质量的关系.方法 随机选择在使用常规130μm刀头行LASIK治疗后剩余角膜基质床厚度<280 μm的50例高度近视患者分为两组.使用超薄角膜瓣LASIK治疗的患者设为A组:25例(50只眼);球镜度-6.00～-10.0 D,平均-7.18 D;柱镜度0～-2.00 D,平均-0.84 D.使用LASEK治疗的患者设为B组:25例(50只眼);球镜度-6.00～-10.00D,平均-7.15 D;柱镜度0～-2.00 D,平均-0.96 D.两组各指标分别于治疗后1周、1、3、6、12个月检查角膜地形图、波阵面像差改变等并进行比较.结果 术后6个月时两组角膜地形图形态都以中央对称均匀型为最多.两组术后1周SimK等效值、SimK差值均较术前减小,差异有显著意义;但术后各期之间及两组之间比较,差异无显著意义.两组手术方式术后1周SAI及SRI值与术前相比,术后各期之间比较,两组之间术后各期比较,差异均无显著性.两组术后1周时各高阶像差和总高阶像差均较术前增加,差异均有统计学意义(P<0.05).两组术后1个月时各高阶及总高阶像差与术前比较,术后1、3、6及12个月之间比较,差异无统计学意义.两组之间比较:在术后1周两组之间比较,B组的各高阶像差和总高阶像差均较超薄瓣LASIK的值大,且3、5、6、7阶差异有统计学意义.在术后1、3、6及12个月比较,LASEK组的各高阶像差和总高阶像差均较超薄瓣LASIK的值小,但差异无统计学意义.结论 超薄瓣LASIK和LASEK对于角膜相对较薄的高度近视眼患者来说,都是安全和有效的手术.两者在角膜地形图及波前像差的各项指标比较中无明显差异.     

近视及近视散光眼高阶像差的研究

目的分析近视及近视散光眼高阶像差的分布特点,探讨高阶像差的相关因素,为个体化切削术前病例合理筛选提供客观依据。方法利用Allegretto Wavelight Ana-lyzer像差仪对来我中心欲行准分子激光原位角膜磨镶术(laser situ in keratomileusis,LASIK)的142例(273眼)近视及近视散光患者进行波阵面像差检测并分析结果。结果①4mm瞳孔直径下垂直像差C7与最佳矫正视力(best correctivevision acuity,BSCVA)呈负相关(r=-0.147,P=0.05)。水平彗差C8在不同瞳孔直径下与BSCVA无明显相关性。球差C12在6 mm瞳孔直径下与BSCVA呈负相关(r=-0.151,P=0.044)。②左右眼之间高阶像差比较差异无显著性(P>0.05),男女性别之间高阶像差RMS 3-6比较差异无显著性(P>0.05)。③C7与年龄呈明显负相关(P<0.01),C8与年龄无明显相关性(P>0.05),C12与年龄呈明显正相关(P<0.01)。④RMS3、RMSh与柱镜呈明显正相关(P<0.05),RMS4与球镜无明显相关性(P>0.05)。RMS5在瞳孔大于6mm时与柱镜呈明显正相关(P<0.05),RMS6在瞳孔大于6mm时与球镜呈明显正相关(P<0.05)。结论①眼别与性别对近视及近视散光眼的高阶像差无明显影响。②C7主要受散光和年龄影响,C12主要受年龄影响。③对欲行个体化角膜切削的近视患者,术前除了要考虑总的高阶像差、角膜的不规则性,大瞳孔和再次手术修补等适应证外,还应考虑C7、C12和年龄等因素,综合制订切削方案。     

Segmentation and accuracy in copying and drawing: Experts and beginners

As part of an ongoing investigation into real-world copying and drawing, I recorded the eye-hand drawing strategies of 16 subjects with drawing experiences ranging from expert to novice while they copied a line drawing of a standing nude. The experts produced accurate copies whereas all the beginners produced marked inaccuracies of overall scaling, proportion and shape. Analysis of eye and hand movements showed that the experts alone segmented the original drawing into simple line sections that were copied one at a time using a direct eye-hand strategy not requiring intermediary encoding to visual memory. The results suggest that segmentation into simple lines defines the task-specific process of accurate copying, and that this process is restricted to experts, i.e. acquired through training and practice. Additional preliminary tests also suggest that a similar process may apply to drawing a model from life.     

Paraneoplastic and non-paraneoplastic retinopathy and optic neuropathy: Evaluation and management

Paraneoplastic syndromes involving the visual system are a heterogeneous group of disorders occurring in the setting of systemic malignancy. Timely recognition of one of these entities can facilitate early detection and treatment of an unsuspected, underlying malignancy, sometimes months before it would have otherwise presented, and gives the patient an increased chance at survival. We outline the clinical features, pathogenesis, and treatment strategies for the retinal- and optic nerve–based paraneoplastic syndromes: cancer-associated retinopathy; melanoma-associated retinopathy; paraneoplastic vitelliform maculopathy; bilateral diffuse uveal melanocytic proliferation; paraneoplastic optic neuropathy; and polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome. Distinguishing these disorders from their non-paraneoplastic counterparts (e.g., autoimmune-related retinopathy and optic neuropathy, and acute zonal occult outer retinopathy) and determining appropriate systemic evaluation for the responsible tumor can be challenging. In addition, we discuss the utility and interpretation of autoantibody testing.     

Sensitivity to first- and second-order motion and form in children and adults

We compared the sensitivity of adults and children aged 3-10 years to first- and second-order motion and form. For first-order stimuli, at all ages sensitivity was better for motion than form, and motion thresholds were better at 6 Hz than at 1.5 Hz. For second-order stimuli, at all ages sensitivity was better for form than motion, and motion thresholds were better at 0.25 cyc/deg than at 1 cyc/deg. Thresholds became adult-like later for motion than for form and later for first-order than second-order stimuli. For first-order stimuli, the changes with age were larger and more protracted.     

Nodes and nodal points and lines in eyes and other optical systems

The typical stigmatic optical system has two nodal points: an incident nodal point and an emergent nodal point. A ray through the incident nodal point emerges from the system through the emergent nodal point with its direction unchanged. In the presence of astigmatism nodal points are not possible in most cases. Instead there are structures, called nodes in this paper, of which nodal points are special cases. Because of astigmatism most eyes do not have nodal points a fact with obvious implications for concepts, such as the visual axis, which are based on nodal points. In order to gain insight into the issues this paper develops a general theory of nodes which holds for optical systems in general, including eyes, and makes particular allowance for astigmatism and relative decentration of refracting elements in the system. Key concepts are the incident and emergent nodal characteristics of the optical system. They are represented by 2 × 2 matrices whose eigenstructures define the nature and longitudinal position of the nodes. If a system's nodal characteristic is a scalar matrix then the node is a nodal point. Otherwise there are several possibilities: Firstly, a node may take the form of a single nodal line. Second, a node may consist of two separated nodal lines reminiscent of the familiar interval of Sturm although the nodal lines are not necessarily orthogonal. Third, a node may have no obvious nodal line or point. In the second and third of these classes one can define mid-nodal ellipses. Astigmatic systems exist with nodal points and stigmatic systems exist with no nodal points. The nodal centre may serve as an approximation for a nodal point if the node is not a point. Examples in the Appendix , including a model eye, illustrate the several possibilities.     

Nutritional antioxidants and age-related cataract and maculopathy

Loss of vision is the second greatest, next to death, fear among the elderly. Age-related cataract (ARC) and maculopathy (ARM) are two major causes of blindness worldwide. There are several important reasons to study relationships between risk for ARC/ARM and nutrition: (1) because it is likely that the same nutritional practices that are associated with prolonged eye function will also be associated with delayed age-related compromises to other organs, and perhaps, aging in general, (2) surgical resources are insufficient to provide economic and safe surgeries for cataract and do not provide a cure for ARM, and (3) there will be considerable financial savings and improvements in quality of life if health rather than old age is extended, particularly given the rapidly growing elderly segment of our population. It is clear that oxidative stress is associated with compromises to the lens and retina. Recent literature indicates that antioxidants may ameliorate the risk for ARC and ARM. Given the association between oxidative damage and age-related eye debilities, it is not surprising that over 70 studies have attempted to relate antioxidant intake to risk for ARC and ARM. This article will review epidemiological literature about ARC and ARM with emphasis on roles for vitamins C and E and carotenoids. Since glycation and glycoxidation are major molecular insults which involve an oxidative stress component, we also review new literature that relates dietary carbohydrate intake to risk for ARC and ARM. To evaluate dietary effects as a whole, several studies have tried to relate dietary patterns to risk for ARC. We will also give some attention to this emerging research. While data from the observational studies generally support a protective role for antioxidants in foods or supplements, results from intervention trials are less encouraging with respect to limiting risk for ARC/ARM prevalence or progress through antioxidant supplementations, or maintaining higher levels of antioxidants either in diet or blood. Without more information it is difficult to parse these results. It would be worthwhile to determine why the various types of studies are not yielding similar results. However, there are many common insults and mechanistic compromises that are associated with aging, and proper nutrition early in life may address some of these compromises and provide for extended youthful function later in life. Indeed, proper nutrition, possibly including use of antioxidant supplements for the nutritionally impoverished, along with healthy life styles may provide the least costly and most practical means to delay ARC and ARM. Further studies should be devoted to identifying the most effective strategy to prevent or delay the development and progress of ARC/ARM. The efforts should include identifying the right nutrient(s), defining useful levels of the nutrient(s), and determining the age when the supplementation should begin.     

Ethics and optometry: concepts and applications

Ethics refers both to the study of behaviour, and moral principals. The related concepts of justice and law are also relevant to optometry. A profession typically claims specialist knowledge and ethical behaviour – putting the interests of clients above its own. However, professional codes fail as ethical directives, and their goals are questioned. Beginning with broad principles, institutional ethics and issues of general health care provision are considered, and applications to optometry are made. Ethical theory can guide us in interacting with our patients, utilising resources and ordering priorities. The conservative approach to consumerism and advertising is defended on the basis of protecting public and professional interests. Ethical behaviour can be fostered, and this process should begin in undergraduate education.     

Exogenous attention and color perception: performance and appearance of saturation and hue

Exogenous covert attention is an automatic, transient form of attention that can be triggered by sudden changes in the periphery. Here we test for the effects of attention on color perception. We used the methodology developed by Carrasco, Ling, and Read [Carrasco, M., Ling, S., & Read, S. (2004). Attention alters appearance. Nature Neuroscience, 7 (3) 308-313] to explore the effects of exogenous attention on appearance of saturation (Experiment 1) and of hue (Experiment 2). We also tested orientation discrimination performance for single stimuli defined by saturation or hue (Experiment 3). The results indicate that attention increases apparent saturation, but does not change apparent hue, notwithstanding the fact that it improves orientation discrimination for both saturation and hue stimuli.     

Aberration and contrast sensitivity comparison of aspherical and monofocal and multifocal intraocular lens eyes

BACKGROUND: Higher-order aberrations and contrast sensitivity were evaluated in patients who underwent phacoemulsification cataract extraction followed by implantation of aspherical, monofocal or multifocal intraocular lens (IOL) replacements. METHODS: In this comparative trial, 124 patients with an average age of 66.8+/-5.2 years and their 124 eyes were randomly divided into three surgical implantation groups to receive one of three types of IOLs in replacement of cataract lenses. The patients of group 1 were given an aspherical IOL Z9001 (AMO, Santa Ana, CA, USA) replacement, and group 2 was implanted a monofocal IOL SA60AT (Alcon, Fort Worth, TX, USA) and group 3 the multifocal IOL SA40N (AMO). Post-surgical best-corrected visual acuity, corneal aberrations, total ocular aberrations, pupil diameters, capsulorhexsis sizes and contrast sensitivity were measured and compared. RESULTS: There was no statistical difference for mean best-corrected visual acuity, pupil diameter, curvilinear capsulorhexis size and corneal aberration among the three groups. For the spherical aberration, fourth-order higher-order aberration and total ocular higher-order aberration, the SA40N group was higher than the SA60AT group and the SA60AT group was higher than the Z9001 group, and the differences between the three groups were statistically significant for these measurements. Contrast sensitivity was higher for the Z9001 group than the SA60AT group and the SA60AT group was higher than the SA40N group, and the difference was statistically significant in all the spatial frequencies of 3, 6, 12 and 18. CONCLUSIONS: Although the multifocal IOL can provide near vision, it can increase higher-order aberration and negatively influence contrast sensitivity. However, the aspherical IOL can reduce aberration and improve contrast sensitivity as compared with the monofocal IOL.