Intraocular Lens Design Research Articles

Artificial accommodating intraocular lens powered by an ion polymer-metal composite actuator.

The current method of controlling the focus of an accommodating intraocular lens is based on ciliary muscle contraction and cannot be used in older patients with presbyopia. We aimed to develop a dynamically accommodating intraocular lens powered by a membrane-shaped ion polymer metal composite actuator that is thin enough to be inserted in the eye. This study addresses two key problems identified in our previous accommodating intraocular lens prototype: the lack of repeatability due to the use of swine lenses instead of artificial lenses and the occurrence of a sixth order aberration. Thus, we present a new accommodating intraocular lens design and a method to transfer energy to actuators. To accommodate lens deformation and depth of focus, we used a membrane-shaped ion polymer metal composite actuator, thin enough to be inserted in the eye, and used an artificial silicone lens. To prevent the sixth order aberration, we included a ring between the ion polymer metal composite actuator and the lens. Different voltage patterns were applied to the IPMC actuator and changes in focus were observed. We were able to obtain repeatability and prevent the sixth order aberration. The dioptric power changed to ±0.23 D when ±1.5 V was used; however, at >1.5 V, a large accommodating range occurred, in addition to astigmatic vision. Thus, we have developed a novel prototype that is completely artificial, allowing reproducible and repeatable results. Visual accommodative demands were successfully met; however, although astigmatic vision was lessened, it was not completely eradicated.

Depth of field measures in pseudophakic eyes implanted with different type of presbyopia-correcting IOLS

To evaluate depth of field (DOF) provided by different presbyopia-correcting intraocular lens (IOL) designs, comparing the results obtained using different criteria for defining the defocus tolerance. A total of 150 eyes undergoing cataract surgery were enrolled and divided into 6 groups depending on the IOL implanted: AT.LISA Tri (Carl Zeiss Meditec), FineVision (PhysIOL), PanOptix (Alcon Laboratories), Tecnis Symfony (Johnson & Johnson Vision), Miniwell (SIFI MedTech) and Tecnis Synergy (Johnson & Johnson Vision). Subjective DOF was obtained from defocus curves with absolute and relative criteria of tolerance of 0.1 logMAR. Aberrometry was also measured and the visual strehl optical transference function (VSOTF) with percentage of degradation of 90%, 80% and 60% was used to quantify objectively the DOF. Tecnis Symfony, Tecnis Synergy and Panoptix IOL groups showed better subjective and objective DOF compared to the rest of IOL groups, being these differences statistically significant differences (p < 0.001). Comparison between subjective and objective DOF showed that subjective measures were higher for all IOLs, being also these differences statistically significant for all groups (p < 0.001). A moderate significant correlation was found between absolute subjective criteria and VSOTF60% (r = 0.73, p < 0.05). Objective and subjective measures of DOF are not comparable due to differences in methodologies and criterions to define the level of degradation tolerance. Nevertheless, both objective and subjective measures showed a trend to a greater DOF for Tecnis Symfony and Tecnis Synergy IOLs compared to most of trifocal diffractive designs, with the exception of PanOptix.

Optical design and performance of a trifocal sinusoidal diffractive intraocular lens.

Two theoretical sinusoidal diffractive profile models to build up a trifocal intraocular lens (IOL) are analysed. Topographic features of the diffractive zones such as their shape, step height and radii, as well as the energy efficiency (EE) of the foci, depends on the particular model, and are compared to the ones experimentally measured in a trifocal lens that claims to be designed with a generic sinusoidal diffractive profile: the Acriva Trinova IOL (VSY Biotechnology, The Netherlands). The topography of the IOL is measured by confocal microscopy. The EE is experimentally obtained through-focus with the IOL placed in a model eye. The experimental results match very accurately with one of the theoretical models, the optimum triplicator, once that a spatial shift in the sinusoidal profile is introduced in the model.

Individual design of aberration-free intraocular lenses.

An analytical tool capable of easily calculating a new aspheric intraocular lens (IOL) (shape factor, aspherization) chosen to be designed as "aberration free" in terms of spherical aberration and/or coma is reported. In terms of retinal image quality, the theoretical performances given by the new proposed IOLs compare well with commercial IOLs.

Simulating Outcomes of Cataract Surgery: Important Advances in Ophthalmology.

As the human eye ages, the crystalline lens stiffens (presbyopia) and opacifies (cataract), requiring its replacement with an artificial lens [intraocular lens (IOL)]. Cataract surgery is the most frequently performed surgical procedure in the world. The increase in IOL designs has not been paralleled in practice by a sophistication in IOL selection methods, which rely on limited anatomical measurements of the eye and the surgeon's interpretation of the patient's needs and expectations. We propose that the future of IOL selection will be guided by 3D quantitative imaging of the crystalline lens to map lens opacities, anticipate IOL position, and develop fully customized eye models for ray-tracing-based IOL selection. Conversely, visual simulators (in which IOL designs are programmed in active elements) allow patients to experience prospective vision before surgery and to make more informed decisions about which IOL to choose. Quantitative imaging and optical and visual simulations of postsurgery outcomes will allow optimal treatments to be selected for a patient undergoing modern cataract surgery.

Progressive-toric IOL design reduces residual astigmatism with increasing pupil size: a ray-tracing simulation based on corneal topography data.

Population studies indicate that astigmatism decreases from the corneal center toward the periphery. A standard toric intraocular lens (IOL) with a constant cylinder power cannot correct uniformly across this gradient. We built an astigmatic eye model based on corneal topography data. A progressive-toric lens with gradually decreasing cylinder power was compared with an identically designed lens but featuring conventional astigmatism correction. Residual astigmatism did not differ significantly (P=0.06) at 3 mm, and the Strehl ratio was identical for both lenses (0.51 ±0.15, P=0.88). At 5 mm, the progressive IOL yielded significantly lower residual astigmatism by 0.10 D (P<0.001). The Strehl ratio was 0.30 ±0.08 with the progressive and 0.29 ±0.08 with the standard lens (P<0.001). At 3 mm, the optical performance was comparable for both IOLs. However, at 5 mm, the progressive-toric was more effective in correcting astigmatism, and it yielded reduced residual astigmatism compared to a standard toric lens.

Repositioning surgery of different intraocular lens designs in eyes with late in-the-bag intraocular lens dislocation.

To evaluate the long-term efficacy and safety after intraocular lens (IOL) repositioning by scleral suturing of 1-piece IOL compared with other IOL designs in the treatment of late in-the-bag IOL dislocation. Patients referred to Oslo University Hospital Oslo, Norway. Prospective cohort study. The study comprised 54 patients (54 eyes) with late in-the-bag IOL dislocation treated with IOL repositioning by scleral sutures (10-0 polypropylene). All operations were performed with an anterior approach and by 1 surgeon. The following IOL designs were repositioned: 1-piece foldable (n = 17), 3-piece foldable (n = 28), plate-haptic (n = 8), and 1-piece rigid (n = 1) IOLs. Patients were evaluated comprehensively preoperatively and at 6 months (80%), 1 year (67%), and 2 years (61%) postoperatively. The main outcome measures were efficacy regarding corrected distance visual acuity (CDVA) and spherical equivalent (SE) and safety regarding complications. Postoperative visual acuity was similar for different IOL designs. The mean SE change to final observation was -0.08 (95% CI, -0.93 to 0.77) in the 1-piece IOL group (n = 11) and -0.98 (-1.73 to -0.23) in the 3-piece IOL group (n = 18) (P = .11). Regarding safety, no patients had uveitis-glaucoma-hyphema syndrome, retinal detachment, or endophthalmitis. The 3-piece IOL group had 1 case of redislocation and 1 case of iritis. No patients had symptoms related to clinical IOL decentration. Long-term intraocular pressure remained within normal limits with overlapping 95% CIs for different IOLs. Repositioning surgery of 1-piece IOLs seems as efficient and safe as that for other IOL designs in the treatment of late in-the-bag IOL dislocation.

Cases of intraocular lens opacification in pseudophakic eyes: analysis of the results of microstructural studies

Relevance. Currently, all over the world, during cataract surgeries, a huge number of intraocular lenses (IOLs) made of different materials are implanted. Alongside with the development of modern IOL materials and designs, publications about their opacities appear. The nature and the localization of IOL opacities mainly depend on the properties of the material out of which the lens is made. Polymethyl methacrylate (PMMA) currently rarely used to manufacture IOLs, tends to cloud in the optical center due to structural breakdown, forming snowflake-like cracks. Opacities of acrylic IOLs depend on the degree of hydrophilic properties of the material. The deposition of crystalline deposits in the optical zone of hydrophilic acrylic lenses leads to a significant decrease in visual acuity and requires IOL explantation. There is a definite dependence of the occurrence of opacities in hydrophilic acryl on the patients concomitant diseases. In hydrophobic acrylic IOLs, vacuoles form, and glistenings occurs. Herewith, visual functions, as a rule, do not suffer.&#x0D; Purpose: to find out what structural changes in the IOL led to the need to remove them from pseudophakic eyes due to a decrease in visual acuity.&#x0D; Materials and methods. Four clouded IOLs made from different materials were examined. The lenses were studied using a SUPRA 55VP scanning electron microscope (Carl Zeiss, Germany) using a secondary electron detector. Element distribution maps on the surface and inside the lenses were collected using an X-max 80 mm2 energy dispersive X-ray analysis detector (Oxford Instruments, UK).&#x0D; Results. A hydrophilic lens with hydrophobic coating became cloudy 5 years after implantation. Hydroxyapatite crystals were found on all parts of the IOL along its surface. In a hydrophobic acrylic IOL, microvacuoles and cavities in the optical center were found using scanning electron microscopy. Two PMMA IOLs underwent self-destruction within 8 years after implantation. Chemical analysis of PMMA lenses did not reveal any inorganic compounds.&#x0D; Conclusion. One of the complications of IOL implantation is an impairment of their transparency. Factors associated with IOL material and manufacturing, as well as the patients comorbidities, can lead to lens opacification at various terms after surgery.

Optical aberrations in three different intraocular lens designs of a same platform

PURPOSE:To compare internal optical aberrations between three different intraocular lenses (IOL) of the same Tecnis platform: monofocal ZCB00, multifocal ZMB00, and enlarged depth-of-focus (EDoF) Symfony ZXR00.METHODS:We included in this study 236 eyes of 118 patients who had been bilaterally implanted either with the monofocal, the multifocal, or the EDoF IOL. They were examined with the K1-RW wavefront analyzer (Topcon Medical Systems) 2 months after surgery. Patients with any ocular pathology were excluded from the study. Only high-order aberrations (HOA) of the third and fourth orders of the Zernike polynomials were considered.RESULTS:Forty-three patients (86 eyes) were implanted with the monofocal IOL, 45 patients (90 eyes) with the ZMB00 IOL, and 30 patients (60 eyes) with the EDoF Symfony IOL. Mean age was 62.42 ± 7.38, 63.60 ± 6.01, and 64.74 ± 5.84 years, respectively. Mean axial length was 23.37 ± 1.00, 23.49 ± 1.00, and 23.54 ± 0.73 mm, respectively. For a 6-mm pupil, internal total HOA in the monofocal group was 1.01 ± 1.75 μm; in the bifocal group was 1.35 ± 2.12 μm; and in the Symfony group was 0.72 ± 0.63 μm. No optical aberration differences were found among the three groups (P > 0.05).CONCLUSION:There are no differences regarding internal optical aberrations between these three IOLs when analyzing them with optical aberrometry. Patients’ pupil size should be considered for the selection of the most appropriate IOL to be implanted, because despite a same optical platform, every IOL implies a different increase of HOA with larger pupil sizes.

Optimum design of the hybrid (diffractive/refractive) multifocal intraocular lenses implanted within human eye

The human eye natural crystalline lens becomes opaque due to cataract. For improvement of the eye vision, the crystalline lens is typically surgically removed and replaced by an intraocular lens (IOLs). The optimum design of hybrid multifocal intraocular lenses (MIOLs) implanted within the human eye model is proposed. The AR40N acrylic MIOLs material has good biocompatibility. Two types of hybrid MIOLs (diffractive/refractive (D/R) and refractive/ diffractive (R/D)) with four foci were designed and evaluated. A comparison between the image quality for a healthy eye (Liou &amp; Brennan model) and an eye with the implanted hybrid MIOLs has been performed based on ZEMAX-EE optical software. The image characteristics, point spread function (PSF), modulation transfer function (MTF), blur spot size, and longitudinal chromatic aberration (LCA) were used as an image criterion in this study. The eye pupil diameter was “3 mm,” the visual field of view was 5 degrees, and the light spectral region was 455- 655 nm. Results indicate that both hybrid MIOLs models achieved good visual acuity (sharp vision) for distances within the range 25 to 108 cm. The MIOLs made a remarkable correction in chromatic aberration than the healthy eye. The MTF for R/D-MIOL model improves the visual quality more than D/R-MIOL and healthy eye models.

Prospective study to compare axial position stability after fellow-eye implantation of 2 distinct intraocular lens designs.

To compare the dynamics of axial intraocular lens (IOL) position and stability in the capsular bag after fellow-eye implantation of a 1-piece C-loop and a 4-point haptic IOL. Hanusch Hospital, Vienna. Prospective, comparative, randomized bilateral study. One hundred eyes of 50 patients were randomly implanted with a C-loop IOL (CT LUCIA 611P) in 1 eye and a 4-point haptic IOL (CT ASPHINA 409MP) in the other eye. Anterior chamber depth (ACD) was measured at 1 week (W1), 1 month (M1), and 4 to 6 months (M4-6) postoperatively using a swept-source optical coherence tomography device (IOLMaster 700). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity, and subjective refraction outcomes were assessed at M4-6 postoperative follow-up. Hundred eyes of 50 patient were included. Pseudophakia ACD values at W1, M1, and M4-6 timepoints were significantly different in eyes implanted with the C-loop IOL compared with the 4-point haptic IOL (P < .001). The overall IOL shift was 0.25 ± 0.16 mm for the 4-point haptic IOL and 0.14 ± 0.09 mm for the C-loop IOL (P < .001). The M4-6 mean monocular UDVA outcome for eyes with C-loop IOL was 0.06 ± 0.14 logarithm of the minimum angle of resolution (logMAR) and 0.03 ± 0.10 logMAR for the eyes with 4-point haptic IOL. M4-6 mean spherical equivalent was -0.32 ± 0.48 diopter (D) in the C-loop IOL group and -0.33 ± 0.42 D in the 4-point haptic IOL group. Statistically significant differences in IOL design results in different postoperative ACD values. No relevant or statistically significant differences were found in refraction or visual acuity between the groups.

Misalignment and tilt effect on aspheric intraocular lens designs after a corneal refractive surgery.

PurposeTo numerically evaluate and compare the tolerance to misalignment and tilt of aspheric intraocular lenses (IOLs) designed for three eyes: with standard cornea and with simulated corneas after myopic and hyperopic laser ablation surgery.MethodsThree aspheric IOLs of +20.00 diopter (D) with different spherical aberration (SA) () values have been designed using a theoretical model eye. Drastic changes on the theoretical eye anterior corneal asphericity have been performed to simulate myopic and hyperopic refractive surgeries. The effect of IOL misalignment and tilt on the image quality has been evaluated using a commercial optical software design for the three eye models. Image quality was assessed from the modulation transfer function (MTF), root mean square (RMS) values of defocus, astigmatism, coma and spherical aberration (), and retinal images obtained from a visual simulator using an aleatory optotype of 0.00 LogMar visual acuity (VA).ResultsIOL misalignment and tilt reduced MTF values in general, and increased wavefront aberrations errors. Aberration-free IOLs maintained best the MTF values when misalignments were applied, together with good on-axis optical quality. IOLs with negative SA () correction decreased the MTF value under 0.43 for misalignments values higher than 0.50 mm with the three corneas. The effect of misalignment on RMS astigmatism and coma was correlated with the IOL SA () and with the three corneas.ConclusionsThis theoretical study shows that the largest degradation in image quality arises for the IOL with the highest amount of spherical aberration (). Moreover, it has been found that the aspherical design has a more influential role in misalignment tolerance than in tilt tolerance.

Longitudinal Chromatic Aberration in Patients Implanted With Trifocal Diffractive Hydrophobic IOLs.

To measure the in vivo longitudinal chromatic aberration (LCA) from the chromatic difference of focus (480 to 700 nm) using psychophysical methods in patients bilaterally implanted with a hydrophobic trifocal intraocular lens (IOL). Psychophysical best focus was measured in both eyes at different wavelengths (480 to 700 nm) and at three different viewing distances (0.00, +1.75, and +3.50 diopters [D]) using a custom-developed polychromatic adaptive optics set-up provided with a supercontinuum laser, a Hartmann-Shack wavefront sensor, a deformable mirror, a motorized Badal system, a pupil monitoring system, and a psychophysical channel with monochromatically illuminated stimuli. Measurements were performed on 10 patients (20 eyes) bilaterally implanted with hydrophobic trifocal diffractive IOLs (FineVisionHP POD F GF; PhysIOL). LCA was computed from the chromatic difference of focus curves as the difference between 480 and 700 nm at near, intermediate, and far. The LCA from psychophysical measurements was significantly higher for far vision (0.99 ± 0.06 diopters [D]), than for intermediate (0.67 ± 0.10 D) and near (0.23 ± 0.08 D) vision (one-way analysis of variance, P < .05). LCA for far vision was significantly higher than for intermediate and near vision in hydrophobic trifocal diffractive IOLs, in agreement with a previous study with the same optical design but hydrophilic material IOLs. The LCA for the hydro-phobic IOL is slightly higher than for the hydrophilic IOL at far. Different combinations of refractive and diffractive LCA will allow optimizing IOL designs to improve polychromatic image quality. [J Refract Surg. 2020;36(12):804-810.].

Altered stress field of the human lens capsule after cataract surgery

The lens capsule of the eye is important in focusing light onto the retina during the process of accommodation and, in later life, housing a prosthetic lens implanted during cataract surgery. Though considerable modeling work has characterized the mechanics of accommodation, little has been done to understand the mechanics of the lens capsule after cataract surgery. As such, we present the first 3-D finite element model of the post-surgical human lens capsule with an implanted tension ring and, separately, an intraocular lens to characterize the altered stress field compared to that in a model of the native lens capsule. All finite element models employed a Holzapfel hyperelastic constitutive model with regional variations in anisotropy. The post-surgical lens capsule demonstrated a dramatic perturbation to the stress field with mostly large reductions in stresses (except at the equator where the implant contacts the capsule) compared to native, wherein maximal changes in Cauchy stress were −100% and −145% for the tension ring and intraocular lens, respectively. However, implantation of the tension ring produced a more uniform stress field compared to the IOL. The magnitudes and distribution of the perturbed stress field may be an important driver of the fibrotic response of inhabiting lens epithelial cells and associated lens capsule remodeling after cataract surgery. Thus, the mechanical effects of an implant on the lens capsule could be an essential consideration in the design of intraocular lenses, particularly those with an accommodative feature.

Effect of haptic geometry in C-loop intraocular lenses on optical quality

The biomechanical stability of intraocular lenses (IOLs) must achieve high-quality optical performance and clinical outcomes after cataract surgery. For this reason, the quality and performance features of the IOLs should be previously analysed following the Standard ISO 11979-2 and ISO 11979-3. The ISO 11979-3 tries to reproduce the behaviour of the IOL in the capsular bag by compressing the lens between two clamps. With this test, it has been demonstrated that the haptic design is a crucial factor to obtain biomechanical stability. Hence, the main goal of this study was to design an aberration-free aspheric IOL and to study the influence of haptic geometry on the optical quality. For that purpose, 5 hydrophobic IOLs with different haptic design were manufactured and their biomechanical stability was compared experimentally and numerically. The IOLs were classified as stiff and flexible designs depending on their haptic geometry. The biomechanical response was measured by means of the compression force, the axial displacement, the angle of contact or contact area, the decentration, the tilt and the strain energy. The results suggest that in vitro and in silico compression tests present similar responses for the IOLs analysed. Furthermore, the flexible IOL designs presented better biomechanical stability than stiff designs. These results were correlated with the optical performance, where the optical quality decreases with worst biomechanical stability. This numerical methodology provides an indisputable advance regarding IOL designs, leading to reduce costs by exploring a feasible space of solutions during the product design process and prior to manufacturing.

Opacification of an accommodative silicone intraocular lens in asteroid hyalosis

A case of opacification of an accommodating silicone intraocular lens (IOL) (Crystalens AO) in a patient with asteroid hyalosis (AH) is presented. A review the literature on dystrophic calcification of silicone IOLs and suggested management for improving visual symptoms in patients with this complication is discussed. Pathology of the explanted IOL of a 57-year-old man confirmed the presence of calcium. A review of the literature disclosed 37 other cases (eyes) of dystrophic calcification in the context of AH. Various IOL designs and manufacturers were reported. Of the 37 cases reported, none included an accommodating silicone IOL implant. To the authors′ knowledge, this is the first reported case of an accommodating silicone IOL to opacify in the presence of AH. Based on the literature review, silicone IOLs are at risk for opacification and should be avoided or used with extreme caution in patients with AH. In addition, YAG capsulotomy might hasten posterior IOL calcification, rendering IOL exchange more challenging.

Customised Selection of the Haptic Design in C-Loop Intraocular Lenses Based on Deep Learning.

In order to increase the probability of having a successful cataract post-surgery, the customisation of the haptic design of the intraocular lens (IOL) according to the characteristics of the patient is recommended. In this study, we present two prediction models based on deep neural networks (DNNs). One is capable of predicting the biomechanical stability of any C-loop IOL, whereas the other can predict the haptic design that fits a desired biomechanical response, enabling the selection of the optimal IOL as a function of the IOL diameter compression. The data used to feed the networks has been obtained from a validated finite element model in which multitude of geometries are tested according to the ISO 11979-3 compression test, a standard for the mechanical properties of the IOLs. The biomechanical response model provides a very high accurate response (Pearson's r = 0.995), whilst the IOL haptic design model shows that several IOL designs can provide the same biomechanical response (Pearson's r = 0.992). This study might help manufacturers and ophthalmologists both analyse any IOL design and select the best IOL for each patient. In order to facilitate its application, a graphical user interface (GUI) was created to show the potential of deep learning methods in cataract surgery.

Posterior capsule opacification: What's in the bag?

Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.

THE EFFECT OF VISCOELASTIC ON SHORT TERM STABILITY OF TORIC INTRA OCULAR LENSES

The advancement in intraocular lens (IOL) design in addition to surgical procedures has elevated the expectations of patients for exceptional postoperative vision and complete spectacle independence after cataract surgery.Available toric IOLs:Standard toric IOLs are available in cylinder powers of 1.5D to 6.00D.they are usually intended for regular corneal astigmatism in arrange from 0.75D to 4.75DApplication of viscoelastic substances in cataract surgery aims mainly to prevent loss of the corneal endothelium. This purpose is achieved through deepening of the anterior chamber, protection of the endothelial cells from surgical trauma mechanically and coating of IOL. To simplify, Ovds can be divided into 4 broad categories: I) Dispersives, II) Cohesives, III) Combination agents and IV) Visco-adaptives.Alcon's VERION Digital Marker:It is atype of digital marking used for aligning of the toric IOL. The VERION system matches the preoperative photograph with the eye intraoperatively using scleral vessels, limbal vessels and iris features.

Effect of Intraocular Lens Tilt and Decentration on Visual Acuity, Dysphotopsia and Wavefront Aberrations.

Tilt and decentration of intraocular lenses (IOL) may occur secondary to a complicated cataract surgery or following an uneventful phacoemulsification. Although up to 2–3° tilt and a 0.2–0.3 mm decentration are common and clinically unnoticed for any design of IOL, larger extent of tilt and decentration has a negative impact on the optical performance and subsequently, the patients’ satisfaction. This negative impact does not affect various types of IOLs equally. In this paper we review the methods of measuring IOL tilt and decentration and focus on the effect of IOL tilt and decentration on visual function, in particular visual acuity, dysphotopsia, and wavefront aberrations. Our review found that the methods to measure the IOL displacement have significantly evolved and the available studies have employed different methods in their measurement, while comparability of these methods is questionable. There has been no universal reference point and axis to measure the IOL displacement between different studies. A remarkably high variety and brands of IOLs are used in various studies and occasionally, opposite results are noticed when two different brands of a same design were compared against another IOL design in two studies. We conclude that <5° of inferotemporal tilt is common in both crystalline lenses and IOLs with a correlation between pre- and postoperative lens tilt. IOL tilt has been noticed more frequently with scleral fixated compared with in-the-bag IOLs. IOL decentration has a greater impact than tilt on reduction of visual acuity. There was no correlation between IOL tilt and decentration and dysphotopsia. The advantages of aspheric IOLs are lost when decentration is >0.5 mm. The effect of IOL displacement on visual function is more pronounced in aberration correcting IOLs compared to spherical and standard non-aberration correcting aspherical IOLs and in multifocal versus monofocal IOLs. Internal coma has been frequently associated with IOL tilt and decentration, and this increases with pupil size. There is no correlation between spherical aberration and IOL tilt or decentration. Although IOL tilt produces significant impact on visual outcome in toric IOLs, these lenses are more sensitive to rotation compared to tilt.