Hydrogel Lenses Research Articles

Extended release of ciprofloxacin from commercial silicone-hydrogel and conventional hydrogel contact lenses containing vitamin E diffusion barriers.

Vitamin E could be used as a coating with commercial silicone hydrogel lenses to extend the release of various ophthalmic drugs. This concept could provide a promising approach to improve overall ocular therapeutic outcomes for topical ocular drugs. This study aimed to develop a contact lens-based ocular drug delivery system using vitamin E as a diffusion barrier to extend the release duration of ciprofloxacin. Five commercial lenses were soaked for 24 hours in various concentrations of vitamin E dissolved in ethanol (0.0125 to 0.2 g/mL). The lenses were loaded with ciprofloxacin for 24 hours in 3 mL of 3 mg/mL of ciprofloxacin/acetic acid solution. The drug release was evaluated in 3 mL of phosphate-buffered saline solution. At t = 0.5, 1, 2, 4, 6, 8, 12, 16, and 24 hours, the amount of ciprofloxacin released was measured using a UV-VIS spectrophotometer at 270 nm. There was a decrease in ciprofloxacin loading with increasing amounts of vitamin E loaded into the silicone hydrogel lenses. For each lens type, there was an optimal amount of vitamin E loaded that extended the release duration of the drug from 1 hour (without vitamin E) to as long as 16 hours. In contrast, vitamin E loaded into hydrogel lenses had no effect on the amounts of drugs loaded or the release duration. Vitamin E can be used as a diffusion barrier with commercially available silicone hydrogel lenses to provide sustained release of ciprofloxacin. The results suggest that vitamin E may form blockages in channels within a silicone hydrogel lens material, thereby forcing a longer path for drugs to diffuse into and out of the lens material. There is an optimal amount of vitamin E that needs to be loaded to extend the release duration, and this is lens material dependent.

Efficacy of different disinfecting methods for contact lenses against Acanthamoeba castellanii

PurposeTo analyze the efficacy of different disinfecting methods for contact lenses (CL) against Acanthamoeba castellanii (AC) using quantitative PCR (qPCR) based on RNA detection. MethodsThree CL materials: rigid gas permeable (RGP), hydrogel (Hy), and silicone hydrogel (SiHy), were contaminated with 1x105 amoebae/ml and incubated for 24 h at 30 °C. After contamination, pre-cleaning steps were performed before using four maintenance solutions based on hydrogen peroxide (HP), sodium hypochlorite (SH), povidone-iodine (PI), and a multipurpose solution (MS). The pre-cleaning steps involved using a cleaner (20 % isopropyl alcohol) and rinsing the CL. Disinfection systems 1 and 2 involved no cleaner and rinsed the CL with tap water or saline solution, respectively. Systems 3 and 4 included a cleaner and rinsed with tap water or saline, respectively. After cleaning, A. castellanii was extracted and stored for qPCR analysis, using Hsp70 and TPBF genes to detect RNA A. castellanii. Results were presented as the percentage of positives or negatives (presence or absence of amoebae), with a p-value < 0.05 considered statistically significant. ResultsDisinfection system 1 with MS resulted in 56 % positives for RGP lenses and 100 % positives for both hydrogel materials. When MS was combined with a cleaner, 12.5 % positives were found for SiHy and 100 % negatives for Hy and RGP lenses (p < 0.05). PI solution alone yielded 38 % and 12 % positives for hydrogel and silicone hydrogel lenses, respectively, but was 100 % effective when combined with a cleaner. HP and SH, whether combined with a cleaner or not, were effective against AC for all CL materials except HP without a cleaner for Hy lenses. ConclusionAll disinfection methods showed some efficacy against Acanthamoeba on any CL material. The most effective solutions were those based on hydrogen peroxide and sodium hypochlorite. Using a cleaner enhanced the final disinfecting efficacy, especially with the multipurpose solution.

International trends in prescribing silicone hydrogel contact lenses for daily wear (2000–2023): An update

PurposeIntroduced around the turn of the 21st century, silicone hydrogel contact lenses alleviated hypoxic anterior eye complications due to their high oxygen transmissibility. The purpose of this work is to update earlier surveys by describing international trends in silicone hydrogel daily wear contact lens fitting between 2000 and 2023. MethodAn annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023. Data relating to 260,144 daily wear soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of silicone hydrogel daily wear contact lens fitting. ResultsThere has been a dramatic increase in silicone hydrogel daily wear lens fits (p < 0.0001), increasing from 2.8 % of all daily wear soft lens fits in 2000 to 73.7 % in 2023. Of all daily wear soft contact lenses prescribed to males, 44.6 % were silicone hydrogel lenses, compared with 43.5 % for females (p = 0.0146). The mean age of those wearing silicone hydrogel daily wear lenses was 32.0 ± 14.5 years, compared to 30.4 ± 13.6 years for those wearing daily wear hydrogel lenses (p < 0.0001). Between 2019–2023, the average percentage of fits was – (a) material type: silicone hydrogel – 73 %; mid-water content hydrogels – 13 %; high water content hydrogels – 9 %; and low water content hydrogels – 5 %, and (b) lens design: spherical – 44 %, toric – 32 %, multifocal – 17 %, monovision – 4 %, and ‘other’ – 3 %. ConclusionThe dramatic increase in silicone hydrogel contact lens prescribing for daily wear has been commensurate with the introduction of multiple lens brands and an ongoing expansion of lens designs, parameters and replacement frequency options. The balance between silicone hydrogel and hydrogel lens prescribing is perhaps starting to approach an equilibrium.

International trends in prescribing extended wear soft contact lenses (2000–2023): An update

PurposeExtended wear has long been considered as the ultimate contact lens modality in terms of user convenience. The purpose of this work is to update earlier surveys by describing international trends in extended wear soft lens fitting between 2000 and 2023, inclusive. MethodAn annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 282,142 soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of extended wear soft lens fitting. ResultsOver the duration of the work there was a very small decrease in the prescribing of extended wear soft lenses (p < 0.0001). More detailed inspection shows that prescribing of these lenses steadily increased from 5.8 % of all soft lens fits in 2000 to 11.6 % in 2007, then steadily decreased to 5.2 % in 2023. Of all soft contact lenses prescribed to males, 9.2 % were fitted for extended wear, compared with 6.7 % for females (p < 0.0001). The mean age of extended wear soft lens wearers at fitting was 34.7 ± 14.7 years, compared to 31.1. ± 14.10 years for daily soft lens wearers (p < 0.0001). Analysis of 1,948 recent extended wear soft lens fits (2019–2023, inclusive), in terms of material type, revealed that, on average, 86 % and 14 % of extended wear soft lenses were fitted using silicone hydrogel and hydrogel materials, respectively. ConclusionA modest increase in extended wear soft lens prescribing from 2000 to 2007 corresponded with the introduction of high oxygen transmissibility silicone hydrogel lenses. However, prescribing of this lens type declined thereafter, probably due to ongoing concerns over their increased rate of microbial keratitis, resulting in a prescribing rate in 2023 (5.2%) that was little different to that observed in 2000 (5.8%).

Contact Lens that Enabled Early Diagnosis for Diseases Induced by Oxidative Stress and Potassium Ion (K+) in Ocular Tissues

The present study used sensor technology to design a lens that could replace a docto.r It consists of an oxidative stress sensor, a (K+) ion sensor and a pressure sensor placed on a Lotrafilcon A silicone hydrogel lens for early diagnosis, as well as a recording and display device that the user can use on their own, recording 24 hours a day and alerting when needed. Additionally, power will be provided to the sensors for data transmission via an external wireless power transfer device. The oxidative stress sensor detects oxidative stress in the structures of the eye and indicates that the patient may have an abnormal condition like diabetic retinopathy, glaucoma and cataracts. Likewise, the (K +) ion sensor detects the (K +) ion concentration in the ocular cells and detects abnormal conditions where the concentration is elevated. The pressure sensor allows the intraocular pressure of patients diagnosed with glaucoma to be kept under control. This way, diseases can be diagnosed early, and continuous monitoring and control of the disease will be ensured. This will prevent the user from having to make frequent visits to the hospital, while also reducing the workload.

Evaluation of the results of contact lens assisted corneal cross-linking treatment in keratoconus patients with thin corneas.

We aimed to compare the efficacy and safety of accelerated contact lens-assisted cross-linking (CA-CXL) with Lotrafilcon B and Comfilcon A lenses in keratoconus (KC) patients with thin corneas. Retrospective, single-center study. We retrospectively included 51 eyes of 39 KC patients with corneal thickness <400µm after epithelial scraping (Epi-off), who underwent accelerated CA-CXL treatment with Lotrafilcon B (n=20) and Comfilcon A (n=31). Uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest refraction values, corneal topographic data and endothelial cell density were recorded at preoperative and postoperative 1st, 3rd and 6th month controls. CDVA in the Comfilcon A group was higher than CDVA before surgery at 6 months postoperatively (p<0.001). When the two lenses were compared, CDVA was found to be significantly higher in the Lotrafilcon B group in the preoperative, postoperative 1st month and 3rd month values, but there was no significant difference between the postoperative 6th month values (p=0.028, p=0.018, p=0.044, p=0.181, respectively). The maximum keratometry (Kmax) value at the 6th month after surgery in the Comfilcon A group was significantly lower than in the Lotrafilcon B group (p=0,009). There was no significant difference between the endothelial cell density values between the groups (p=0.623, p=0.609, p=0.794, p=0.458, respectively). There was no significant difference between the progression, regression, and stability rates of the two groups (p=0.714). Accelerated CA-CXL with Lotrafilcon B and Comfilcon A silicone hydrogel lenses is a safe and effective method to stop progression in patients with thin corneas.

Vinyl Polymers as Key Materials in Contact Lens Design: A Review of Progress and Future Directions

AbstractVinyl polymers, crucial in contemporary contact lens design, present unique attributes with promising implications for vision correction. This comprehensive review navigates the trajectory and future trajectories of vinyl polymer‐based contact lenses. The introduction underscores the vital role of contact lenses in vision correction and positions vinyl polymers as ideal materials due to their exceptional properties. Delving into material specifics—high oxygen permeability, optical clarity, surface wettability, and mechanical strength—the analysis emphasizes their influence on corneal health, comfort, and durability. The versatility of manufacturing techniques, encompassing spin casting, molding processes, polymerization, and surface modification, underscores their feasibility in crafting high‐quality lenses. Examining clinical applications, encompassing daily disposables, extended wear, silicone hydrogel, and specialty lenses, alongside biocompatibility assessments and user feedback, provides a nuanced understanding of vinyl polymer‐based lens effectiveness. The article candidly addresses challenges—dehydration, deposits, mechanical stability, and durability—alongside regulatory considerations. Future prospects involve novel formulations, smart materials, bioinspired designs, and noninvasive technologies to amplify comfort and performance. In conclusion, this review distills progress, acknowledges challenges, and charts a sanguine course for vinyl polymer materials in advancing contact lens design, envisioning a future marked by enhanced vision correction technologies.

Biogenic Gold Nanoparticle‐Based Antibacterial Contact Lenses for Color Blindness Management

Biogenic gold nanoparticles (BAu NPs) synthesized using olive leaf extract were used as an additive in commercial contact lenses (BAu lens). Their antibacterial and color blindness‐correcting properties were examined. To compare the properties, gold nanocomposite contact lenses were also synthesized using the well‐known Turkevich method (TAu lens). The breath‐ in/breath‐out method was used to load the Au NPs onto commercial contact lenses. The bio‐gold nanoparticles showed good dispersion and stability within the lens hydrogel matrix. Nanoparticle loading had a negligible effect on the contact lenses’ wettability and swelling properties. BAu lens filtered around 55% of visible light at 530 nm, a problematic wavelength for color blind patients. The optical filtering results were comparable with Pilestone commercial color blind correction glasses. BAu lenses also showed superior resistance against the attack of Pseudomonas aeruginosa and Staphylococcus aureus bacteria as compared to Tau lenses. As scanning electron microscopy (SEM) imaging showed, the BAu lenses showed a complete lack of surface attachment toward the bacterial colonies. This research provides a cost‐effective and scalable method of producing multi‐functional nanocomposite contact lenses with antibacterial and color blind correction properties.

Effect of Alpha Lipoic Acid and Pyridine Group on Silicone Hydrogel Lens

Effect of Alpha Lipoic Acid and Pyridine Group on Silicone Hydrogel Lens

Assessment of friction in aged soft contact lenses by an innovative method

In the present research work, we intend to evaluate the effect of aging of CL (contact lenses) on friction and, in case there are alterations in the value of the coefficient of friction after aging, to understand which modifications in the material incite these variations. For this, a simulation of the aging process to which the CL are subject in vivo is carried out and the friction and stiffness of the CL are characterized, before and after aging. The aging procedure of SCLs (soft contact lenses) was simulated by a cycling process considering that the main parameter influencing the material surface is the transition between the closed and open eye and the exposure to environmental aggressions, particularly ultraviolet radiation. The values of the coefficient of friction and elastic modulus before and after the aging process were compared and was verified the increase of both parameters for all contact lenses. The hydrogel lens was the least affected by aging and the silicone - hydrogel lens based on delefilcon A was the one that showed the least stability of properties.

Commentary: Leap forward in presbyopia management - Correcting beyond spectacles.

Commentary: Leap forward in presbyopia management - Correcting beyond spectacles.

Drug-Eluting Sandwich Hydrogel Lenses Based on Microchamber Film Drug Encapsulation.

Corticosteroids are widely used as an anti-inflammatory treatment for eye inflammation, but the current methods used in clinical practice for delivery are in the form of eye drops which is usually complicated for patients or ineffective. This results in an increase in the risk of detrimental side effects. In this study, we demonstrated proof-of-concept research for the development of a contact lens-based delivery system. The sandwich hydrogel contact lens consists of a polymer microchamber film made via soft lithography with an encapsulated corticosteroid, in this case, dexamethasone, located inside the contact lens. The developed delivery system showed sustained and controlled release of the drug. The central visual part of the lenses was cleared from the polylactic acid microchamber in order to maintain a clean central aperture similar to the cosmetic-colored hydrogel contact lenses.

Efficacy of custom-made soft keratoconus lenses on corneal aberrations and photic phenomena in patients with keratoconus: a corneal topography imaging based study.

To evaluate the efficacy of custom-made soft keratoconus (KC) lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC. Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone (Toris K) soft silicone hydrogel lenses. Best spectacle-corrected visual acuity (BSCVA) and contact lens-corrected visual acuity (CLCVA) were recorded. Lower- and higher-order corneal aberrations (LOAs and HOAs) were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones. Mesopic pupil diameter and subjective photic phenomena were also assessed. Mean CLCVA was significantly improved compared to BSCVA (P<0.0001). Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses, except for posterior corneal curvature values. In the 4.5 mm central optical zone, all wavefront aberrations decreased significantly after lens fitting (P<0.0001). In contrast, in the 7 mm (peripheral) optical zone, values for HOAs, spherical and residual aberrations, and optical path differences were increased, while LOAs, trefoil, and quadrifoil coefficients were decreased. The rate of photic phenomena was significantly higher in participants with a pupil size >6.00 mm (85.7%). Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations. This practical and nonsurgical approach appears to be an effective method for the visual management of KC.

Standardization on the Measurement Method of Breaking Strength for the Durability Evaluation of Hydrogel Lenses

본 연구는 다양한 함수율을 가진 하이드로젤 콘택트렌즈를 제조한 후, 기계적 물성 중 하나인 내구성을 측정하였으며, 하이드로젤 렌즈의 파단강도 측정방법에 대한 표준화를 위해 진행되었다. 기본적인 하이드로젤 콘택트렌즈 재료에 친수성과 소수성의 첨가제를 비율별로 첨가하여 제조한 후 제조된 콘택트렌즈의 물성 및 파단강도를분석하였다. 제조된 콘택트렌즈의 파단강도를 측정한 결과, 친수성 재질인 N.N-Dimethylacrylamide [DMA] 의 첨가량이 증가할수록 점차 렌즈의 강도가 감소하였고, 소수성 재질인 Butyl methacrylate [BMA]의 첨가량이 증가할수록 점차 렌즈의 강도가 증가하는 것으로 나타났다. 현재 파단강도를 활용한 콘택트렌즈의 내구성 측정에 관한 규격은 전무한 실정이며, 내구성 측정 방법 중 하나인 인장강도는 재료에 따라 일정하지 않고 정확한측정이 어렵다. 따라서 본 실험 결과로 볼 때, 파단강도를 통해 콘택트렌즈의 내구성 평가를 위한 표준화된 기준이 필요하다고 판단된다.

Standardization Study on Chromaticity Analysis of Ophthalmic Hydrogel Lenses

본 연구는 하이드로젤 콘택트렌즈의 정확한 광학적 특성을 평가하기 위하여 금 나노입자를 첨가하여 착색 콘택트렌즈를 제조하였다. 렌즈제조용 고분자 중합을 위해 2-hydroxyethyl methacrylate(HEMA)와 교차결합제인Ethylene glycol dimethacrylate(EGDMA) 그리고 개시제인 Azobisisobutyronitrile(AIBN)를 기본조합으로 사용하였으며, 렌즈 착색을 위해 금 나노입자를 10 ~ 100nm의 크기 별로 분류하여 첨가 후 중합하였다. 제조된 렌즈의 광학적 특성을 평가하기 위해 분광투과율 및 색도를 각각 측정하여 평가하였으며, 비교 분석하였다. 실험 결과, 측정된 모든 콘택트렌즈의 가시광선 투과율은 90% 이상으로 나타나 모두 우수한 것으로 나타났다. 반면 색도계를 사용한 색도 측정의 경우, 서로 다른 색 좌표 및 명도를 나타내었으며, 따라서 각 렌즈의 색상 농도 및 중합도를 평가하였다. 이 결과로 볼 때 색도계는 분광투과율과 함께 콘택트렌즈의 광학적 특성 평가를 표준화하여 측정한다면 다양한 용도로 적절히 활용될 것으로 판단된다.

Viability studies of hydrogel contact lens on a 3D printed platform as ocular drug delivery carrier for diabetic retinopathy

Diabetic retinopathy (DR) is a microvascular disease that damages retinal layers. Avastin loaded PHEMA hydrogel lens as a topical implant is presented here for DR therapy. The lens is fabricated upon a novel, cost-effective and simple to design 3D printed platform. It has contours similar to a commercial contact lens for patient comfort and added characteristics of a drug delivery vehicle. The lens swelling properties are comparable to the commercial lens. The percentage of cumulative drug released between 0 and 1500 min is 60 %, and the release kinetics follows the Korsmeyer- Pappas (KP) release model with 40–60% anti-VEGF effects.

Ophthalmic Hydrogel Contact Lens Material Containing Magnesium Oxide Nanoparticles and 3-(Trifluoromethyl)styrene for Biomedical Application.

This research was conducted for the synthesis and application of ophthalmic lens materials with improved oxygen permeability and durability. Polyvinylpyrrolidone (PVP), N-vinyl-2-pyrrolidone (NVP), 3-(trifluoromethyl)styrene (3-TFMSt), and magnesium oxide nanoparticles were used as additives for the basic combination of 2-hydroxyethyl methacrylate (HEMA). Additionally, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent and azobisisobutyronitrile (AIBN) as the initiator. The addition of magnesium oxide nanoparticles was found to increase the tensile strength from 0.0631 to 0.0842 kgf/mm2. Copolymerization with a small amount of 3-TFMSt of about 1% increased the tensile strength to 0.1506 kgf/mm2 and the oxygen permeability from 6.00 to 9.64 (cm2/s)∙(mLO2/mL·mmHg)∙10-11. The contact lens material produced using N-vinyl-2-pyrrolidone and magnesium oxide nanoparticles as additives satisfied the basic physical properties required for hydrogel contact lenses and is expected to be used usefully as a material for fabricating high-performance hydrogel lenses.

Rigid Gas Permeable Contact Lens Management of Infantile Aphakia Status-Post Cataract Extraction

Infants born with congenital cataracts require cataract extraction to prevent lifelong visual impairment resulting from deprivational amblyopia. After lensectomy, two optimal corrective treatment options exist: intraocular lens implantation or contact lens correction. This case presentation describes the etiology, treatment, and successful management of a patient with unilateral infantile aphakia with a rigid contact lens. The seven-week-old patient with a congenital cataract of the right eye was referred to our clinic for a contact lens fitting prior to cataract extraction. Surgeons often do not elect to manage aphakia with artificial lens implantation because the correct intraocular lens parameter is difficult to infer in a rapidly growing child, and surgical complications may occur. While glasses are important for when contact lens wear is not indicated, the high prescription required by these aphakic individuals results in significant visual distortion and aniseikonia. Contact lens correction has shown to be a safe and visually effective alternative to treating infantile aphakes. Various material options exist, including rigid gas permeable and soft lenses. While soft hydrogel lenses may appear more comfortable and less intimidating to a parent, limitations exist including restricted parameter availability for commercially produced lenses and reduced oxygen permeability for custom soft lenses. Rigid contact lenses provide optimal visual correction due to their extensive customizability while also offering high oxygen permeability. This lens modality, in conjunction with proper follow-up monitoring and ophthalmological co-management, provided for successful aphakia treatment in our patient. &lt;br&gt;CE Notification: This article is available as a COPE accredited CE course. You may take this course for 1-hour credit. Read the article and take the qualifying test to earn your credit. Click here to Enroll. (https://www.crojournal.com) Please check COPE course expiry date prior to enrollment. The COPE course test must be taken before the course expiry date.

Changes of symptomatology, tear film and ocular surface integrity one week during Somofilcon-A and Omafilcon-A lens wear.

Clinicians play a key role in prescribing contact lenses that best suited for fitting which materials had an impact on ocular surface parameters. The present study aimed to evaluate the impact on symptomatology, tear film dynamics and ocular surface integrity of a silicone-hydrogel (Somofilcon-A) and a hydrogel (Omafilcon-A) lens before and after wearing for one week in contact lens neophyte participants. A Somofilcon-A and Omafilcon-A were randomly fitted to one or other the eye on an initial group of 28 participants. Subjects were scheduled for three sessions: basal session previous fitting, second session after 4-wear hours, and final session after 7-wear days for up to 10 h. In each session, CLDEQ-8, tear meniscus height and hyperemia with and without lenses, as well as lipid layer thickness and corneal/conjunctival staining without lenses were assessed. Values were compared between lenses and sessions. In intrasession comparison, there were no differences in any parameter between materials on any session with or without lenses (all p≥0.176), except on the conjunctival staining where values obtained during Somofilcon-A wear (all p ≤ 0.006). In intersession analysis, CLDEQ-8 score, tear meniscus height and lipid layer thickness showed a statistical difference during both materials wear (all p ≤ 0.009), while conjunctival hyperemia does not (p = 0.237); corneal staining showed differences during Omafilcon-A wear (p = 0.037), contrary to conjunctival staining which showed differences only during Somofilcon-A wear (p < 0.001). Contact lenses wear had an impact on ocular parameters that have some specific influences of the material on which lenses were manufactured.

Affluence and Contact Lens Prescribing.

To assess the impact of national affluence on the extent of prescribing of various types of soft contact lenses. Using information derived from a large bank of contact lens prescribing data, the relationship between the percentage prescribing of daily disposable, toric, silicone hydrogel, and multifocal contact lenses versus the gross domestic product at purchasing parity per capita (GDP [PPP]) was determined for all countries in which contact lens prescribers returned survey forms relating to greater than 100 contact lens fits between 2017 and 2021, inclusive. Data from 39 countries were analyzed, comprising 94,181 contact lens fits. The relationship between percentage contact lens prescribing versus GDP (PPP) was highly statistically significant for daily disposable lenses (r 2 =0.35, P <0.0001), marginally significant for toric lenses (r 2 =0.08, P =0.06), and not significant for silicone hydrogel lenses (r 2 =0.01, P =0.42) or multifocal lenses (r 2 =0.02, P =0.35). The rate of prescribing daily disposable contact lenses, and to a lesser extent toric lenses, is related to national affluence. The contact lens industry, practitioners, and governments/regulatory bodies should remain cognizant of this association and, where possible, reduce cost barriers to the purchase of such contact lens products so that they can be prescribed based on important clinical, refraction, and lifestyle considerations.