Practitioner influence on contact lens prescribing in the UK

Contact lenses are mainly fitted by registered optometrists and contact lens opticians in the UK. Data we have gathered from annual contact lens fitting surveys over the past 12 years indicate that, on average, registered optometrists and contact lens opticians undertake 3.2 and 7.1 contact lens fits per week (p < 0.0001). More experienced practitioners tend to fit older patients. Practitioners fitting more lenses per year tend to fit a higher proportion of soft lenses. Contact lens opticians tend to fit a higher proportion of patients with planned replacement and daily disposable lenses compared with optometrists.     

Review of 20 years of soft contact lens wearer ocular physiology data

BackgroundSince the introduction of Silicone hydrogel (SiHy) contact lenses 20 years ago, industry has continued to modify lens materials, designs, lens care products and manufacturing processes, striving to improve contact lens physiological performance, comfort, and convenience for wearers. The purpose of this study was to investigate whether the ocular health of habitual soft contact lens wearers today is better than it was in previous decades.MethodsBaseline ocular physiology data for 3624 participants from a The Brien Holden Vision Institute clinical trials database were retrospectively reviewed. Records were grouped into 3 time periods; A: >2 decades ago (1997–1999), B: one decade ago (2009–2014) and C: recent years (since 2015). Physiology data for both neophytes and habitual contact lens wearers included; bulbar, limbal and upper palpebral conjunctival redness, corneal and conjunctival staining and conjunctival indentation from contact lenses.ResultsCorneal staining levels are similar between neophytes and contact lens wearers at time points A and C but worse for contact lens wearers at time point B. Limbal redness was greater in contact lens wearers than in neophytes at time point A but at time points B and C they are not different to the non-contact lens wearing population. In recent years, most ocular physiological variables in habitual contact lens wearers are similar to neophytes.ConclusionsWhile there have been changes over the past two decades in ocular physiological responses to contact lens wear, it appears that ocular health with current day contact lens wear is similar to no lens wear in most respects.     

The 75th anniversary of the Tuohy corneal contact lens: A review

The aim of this review is to mark the 75th anniversary of the introduction of the original corneal contact lens of Tuohy in 1948.American documents in the public domain, such as census records and draft registration cards, were consulted in order to provide a more comprehensive biography of Kevin M Tuohy, inventor of the corneal contact lens, than those previously published.Perhaps due to a failure to consult original sources concerning the Tuohy corneal lens, some historical accounts have provided incomplete or incorrect information about its design and dimensions. The back surface specification of the bi-curve Tuohy lens in its standard diameter of 11.50 mm has been tabulated and edge lift and edge clearance values calculated. A colour photograph illustrates the fluorescein pattern of a Tuohy lens.Patients wearing Tuohy lenses were able to achieve a much longer wearing time compared to those wearing sealed scleral lenses since they eliminated corneal epithelial oedema, a frequent problem which necessitated removal of lenses after a few hours of wear due to cloudy vision. Only some of Tuohy lens wearers exhibited an adverse corneal response such as fluorescein staining after 12, or more, hours of wear.The clinical success of the Tuohy lens and the fact that its fitting procedure was simpler and quicker than that for scleral lenses encouraged optometrists to commence contact lens practice and to implement improvements in the design of the corneal lens.     

Contact lens prescribing trends in the UK hospital eye service

PurposeThe aim of this study was to evaluate the types of contact lenses fitted by hospital optometrists within the Midlands region of the United Kingdom (UK).MethodA questionnaire was sent to all the lead optometrists of the Midlands Hospital Optometry Group (MHOG). This group includes optometry hospital eye departments within the Midlands region of the UK. The questionnaire requested information of their last ten contact lens fitting appointments. Details of the patient’s age, gender, lens type, wearing times, and presenting condition were retrospectively taken from the patients’ records using the appointment diary to identify the last ten patients fitted with contact lenses.ResultsDetails from a total of 109 contact lens fits were collected. This included 45 females and 64 males with a mean age of 39.4 ± 17.4 years. The mean wearing time was 6.3 ± 1.0 days per week and 10.7 ± 5.1 h per day. Sixty-one percent of the contact lenses fitted were for patients with keratoconus and over half of all the contact lenses fitted were corneal rigid gas permeable lenses.ConclusionThis study highlighted that the main reason for fitting contact lenses in hospital contact lens practice is primary corneal ectasia, and mainly keratoconus. Whilst most patients with keratoconus were fitted with corneal rigid gas permeable contact lenses, around 1 in 6 were fitted with soft contact lenses. This study addresses a gap in the literature about contact lenses fitted in UK hospitals and how they differ from community contact lens practice.     

Trend of soft contact lens prescribing in an optometry centre in India: A 6-year analysis

This six-year retrospective longitudinal study was conducted to examine the changes in the pattern of prescribing soft contact lenses in an optometry centre located in a University in South India. Details regarding the type of lenses, lens material, wearing pattern and the clinical diagnoses were analyzed from January 2006 to December 2011. A total of 1273 soft contact lens fits (n = 1273) were analyzed. Two-third of the total lenses dispensed was for females and their mean age (24.0 ± 8.3 yrs) was less than that of male (27.0 ± 11.2 yrs) lens users. Nearly 70% of them had myopia and 48% wore conventional soft contact lenses. During the studied six years, the percentage of conventional lenses declined by 60%. This study demonstrated a gradual and significant increase in popularity of disposable contact lenses and silicone hydrogel lens material which is comparable to the global trend.     

Assessment of the reliability (repeatability) of corneal thickness measurements in soft contact lens wearers using a non-contact specular microscope

PurposeTo assess variability across 3 measures of central corneal thickness (CCT) obtained with a non-contact specular microscope and taken over a few minutes from habitual soft contact lens wearers.MethodsOne eye from 200 healthy adults (with an average age of 21 y, half of whom had a 3.5 ± 2.1 year history of successful daily wear of soft contact lenses while the control group had nominally normal eyes) were assessed using the auto-focus Topcon 2000P instrument to obtain an image of the endothelium and CCT.ResultsThe individual CCT values encountered in the 200 subjects ranged from 0.449 mm to 0.591 mm, with the average of 3 measures ranging from 0.459 to 0.591 mm in the control group and between 0.449 and 0.585 mm for the SCL wearers. The group mean CCT values were the same for both groups (at 0.524 mm), but the group mean SD value was marginally higher (at 0.028 mm) for the SCL group as compared to controls (SD = 0.026 mm). The normalized intra-subject variability (as the group-mean coefficient of variation, COV value) was 0.843 ± 0.401 for the control group and higher at 1.08 ± 0.546 for the SCL group (p < 0.001).ConclusionsRepeat measures of central corneal thickness, using a non-contact specular microscope, is very similar to those taken on age-matched non-contact lens wearers. These results may not equally apply to similar pachymetry measures in patients wearing RGP lenses or for older patients wearing soft contact lenses.     

The short-term effect of contact lens wear on blink characteristics

PurposeThe aim of this pilot study was to investigate the initial effect of contact lens wear on spontaneous blink characteristics.MethodsThis was a randomised, crossover pilot study. Spontaneous blinking was recorded using a high-speed infrared camera in ten subjects with three different soft contact lenses (spherical hydrogel, spherical silicone hydrogel and toric hydrogel), one rigid contact lens and without contact lenses. Custom semi-automated software was used to determine palpebral aperture height, interblink interval (IBI), blink speed, blink completeness and blink duration.ResultsThe IBI was significantly greater for non-lens wear compared with the silicone hydrogel [ratio (95% CI): 1.34 (1.16, 1.55), p < 0.0001], toric hydrogel [1.28 (1.10, 1.48), p = 0.0001] and rigid corneal lenses [1.48 (1.27, 1.73), p < 0.0001]. The spherical silicone hydrogel lens showed greater closing-phase speed than non-lens wear [mean difference (95% CI): 27.4 (5.6, 49.1) mm/s, p = 0.006]. Shorter total blink duration was found for non-lens wear compared with any of the lens types [spherical hydrogel: ratio 0.89 (0.81, 0.98), p = 0.01; spherical silicone hydrogel: 0.87 (0.80, 0.95), p = 0.0001; toric hydrogel: 0.90 (0.83, 0.98), p = 0.004; and rigid corneal: 0.88 (0.82, 0.96), p = 0.0004]. Opening-phase speed (p = 0.12) and blink completeness metrics (all p > 0.5) were not influenced by wearing condition.ConclusionThis work showed that short-term contact lens wear influenced the palpebral aperture height, IBI, speed and duration of the blink, and the effect is dependent on the contact lens type. The completeness of the blink was not altered by contact lens wear. Future work should be conducted to assess the effect of long-term wear of different contact lens types on blink characteristics. The measurement of spontaneous blinking characteristics represents an immediate, sensitive and non-invasive evaluation of the impact of a contact lens on the ocular surface.     

Contact lens correction of presbyopia

The ageing population highlights the need to provide effective optical solutions for presbyopic contact lens wearers. However, data gathered from annual contact lens fitting surveys demonstrate that fewer than 40% of contact lens wearers over 45 years of age (virtually all of whom can be presumed to suffer a partial or complete loss of accommodation) are prescribed a presbyopic correction. Furthermore, monovision is prescribed as frequently as multifocal lenses. These observations suggest that an optimal solution to the contact lens correction of presbyopia remains elusive.     

A pilot study investigating the effect of extended contact lens wear on limbal and central corneal morphology

PurposeTo investigate the effect of long-term extended soft contact lens wear on limbal and central corneal cell morphology, and limbal architecture.MethodsEach participant attended a study visit involving in vivo confocal microscopy of central corneal and limbal epithelium. Scans were graded by five masked graders for three features: central epithelial irregularity, limbal epithelial irregularity and the prominence of palisades of Vogt. The variability of grades between different graders and the difference of grades between extended wearers and daily soft/non-contact lens wearers were assessed.ResultsNineteen participants (9 extended soft contact lens wearers and 10 daily soft/non-contact lens wearers) aged 31–65 years were enrolled in this study. Scans from 37 eyes were included in the analysis. Agreement between graders for each feature was moderate to good with inter class correlation >0.7. While there were no significant differences in central epithelial cell irregularity (p = 0.527) and the prominence of palisade of Vogt (p = 0.182) between extended or daily soft/non-contact lens wearers, limbal epithelial cell irregularity showed a trend with increased irregularity in extended soft contact lens wearers (p = 0.091).ConclusionsWhile no differences in limbal cell morphology and structure or central epithelial cell was found in this subjective grading study of extended wearers compared to daily soft/non-contact lens wearers, further studies using a larger sample size or a longitudinal study design are warranted.     

A study of contact lens compliance in a non-clinical setting

PurposeTo evaluate soft contact lens replacement, overnight (ON) wear, and contact lens case compliance in a non-clinical sample.MethodsSubjects (n = 297) were recruited at the Center for Science and Industry (COSI) in Columbus, Ohio. Adult (≥ 18 years) soft contact lens wearers completed a survey about contact lens replacement, ON contact lens wear, and contact lens case replacement habits.ResultsTwo-week replacement lenses (according to the manufacturer’s replacement schedule [MRS]) were most common (45.5%), followed by monthly (34.3%) and daily replacement (20.2%). Non-compliance with replacement schedule was reported in 38.7% of subjects. Age (p = 0.02), years of lens wear (p = 0.02), and MRS (p <0.0001) affected replacement compliance. Post-hoc analysis showed daily replacement wearers were more compliant than two-week (p <0.0001) and monthly (p <0.0001) replacement wearers with prescribed lens replacement. Non-compliance with prescribed ON wear was reported in 23.9% of subjects. Subjects who were non-compliant with lens replacement were more likely to be non-compliant with ON wear (p = 0.02) and had worn contact lenses for less time (p = 0.02). Of the subjects who used contact lens cases, 74.6% were unsure when they should replace their case. Frequency of case replacement was not associated with age (p = 0.5), gender (p = 0.5), years of contact lens wear (p = 0.7), MRS (p = 0.4), replacement compliance (p = 0.3), or ON wear compliance (p = 0.7).ConclusionsDaily replacement wearers were most likely to be compliant with contact lens replacement, but all subjects, including daily replacement wearers, had similar ON wear non-compliance. Non-compliant lens replacement was associated with non-compliant ON wear, but contact lens case replacement was not related to either compliance category. The majority of subjects had no knowledge of proper contact lens case replacement, despite compliance in other categories.     

The effect of tinted soft contact lens wear on functional visual acuity and higher-order aberrations

PurposeTo investigate the differences of functional visual acuity (FVA) and high order aberrations (HOAs) in relation to tinted and clear hydrogel soft contact lens (SCL) wear.MethodsA prospective comparative study was performed in 16 eyes of 16 healthy volunteers. Dynamic visual acuity (using a FVA measurement system) and higher-order aberrations (using a wavefront sensor) were compared in subjects wearing two types of soft contact lenses: 1-day Acuvue^® (Vistakon, Jacksonville, FL) clear and the 1-day Acuvue^® Define^TM (Vistakon, Jacksonville, FL) tinted lens. The blink rates were recorded during FVA testing. The correlation between the difference of HOAs and differences in FVA values was analyzed.ResultsThe mean LogMAR FVA scores with clear and tinted SCLs were 0.07 ± 0.13 and 0.14 ± 0.17 (P < 0.05). The mean blink frequencies with clear and tinted SCL wear were 18.4 ± 8.3 and 25.3 ± 4.7 blinks/min (P < 0.05). Both 3rd-order aberrations and total HOAs showed statistically significant differences between the two types of soft contact lenses for 6 mm pupil measurements (P < 0.05). A significant positive linear correlation was observed between ΔHOAs and ΔLogMAR FVA for 6 mm pupil measurements (R = 0.53, P = 0.04).ConclusionsTinted contact lens wear appears to induce a reduction in optical quality. Functional visual acuity measurement is a useful procedure to study the changes of visual performance and quality in tinted contact lens wear.     

Soft contact lens wearers’ compliance during the COVID-19 pandemic

AimContact lens wearers need to maintain optimal hygiene practices during the COVID-19 pandemic to minimise contact-lens complications including microbial keratitis and corneal infiltrative events. This online survey (UK and Ireland) explored contact lens wearers’ compliance behaviours, attitudes and concerns during the pandemic.MethodThe 60-item anonymous online survey was distributed during a 1-month period via Qualtrics (starting on 14/04/20). The survey captured: a) demographic information, b) type of lenses worn and compliance with lens wear and care procedures, c) adherence to recommendations and d) concerns associated with contact lens wear during the pandemic.ResultsTwo hundred and forty seven responses were received (34.3 ± 11.7 years old, 79% female). Seventy nine percent of participants reported that they were self-isolating or rigorously following social distance advice. Fifty-six percent of participants reported using their lenses less during the pandemic. Eighty-seven percent of respondents reported following the recommended 20-second rule most times/every time and 96% used soap and water during handwashing. Eleven percent of respondents admitted not following recommendations regarding disposal of lenses and 18% would not consider ceasing lens wear if unwell (with flu/cold) during the pandemic.ConclusionRespondents reported wearing their contact lenses less than usual. Good compliance with handwashing was observed but soft reusable lens wearers showed a statistically significant lower compliance with lens wear and care compared to daily disposable lens wearers (p=<0.001).     

Prevalence of contact lens related complications in a tertiary eye centre in India

Aim

To determine the prevalence of contact lens related complications in a tertiary eye care centre in India.

Methods

A retrospective review of the charts of 1255 patients who visited our contact lens clinic during 2001-2004 was conducted. The inclusion criteria included patients of at least 18 years of age, having refractive errors and keratoconus. Exclusion criteria included previous corneal surgeries and pediatric patients. 190 subjects with lens related complications were identified from among 923 patients who were using lenses.

Results

The prevalence of contact lens complications was 20.58%. Females with complications were more common (59.47%). The complications were more common in students. The most common complications were contact lens induced papillary conjunctivitis (CLPC) (6.39%), corneal vascularisation (4%), and superficial punctate keratitis (SPK) (3.5%). The total complications were less prevalent in patients wearing rigid gas permeable (RGP) lenses as compared to soft contact lenses. Infectious keratitis was noted in 8 eyes. Pseudomonas aeuroginosa was the most common organism isolated. The average daily wear with RGP lenses was 11.04 ± 3.7 h and 10.96 ± 3 h with soft contact lens. The highest number of complications was noted in 47.89% patients who were wearing lenses for excess of 11 h. The number of patients with complications arising due to sleeping with the lenses was 74 (38.95%).

Conclusion

Prevalence of contact lens complications was more in soft contact lens wearers compared to RGP wearers. CLPC was the most common complication followed by vascularisation and SPK.     

Ability of patients to recall habitual contact lens products and enhancement of recall using photographic aids

Purpose

To determine the proportion of soft contact lens (CL) wearers who are able to recall their habitual products (lenses and care system) correctly from memory, and to evaluate the value of using photographic aids (PAs) to improve recall.

Methods

103 soft lens wearers attended 2 visits to investigate their habitual CL product use. At the first visit they were asked to recall which products they were using and then to identify their products from PAs. They returned for a second visit with their products for confirmation.

Results

51% correctly reported their lens brands from memory alone, which improved to 87% with the use of the PAs (p < 0.001). 41% correctly reported their habitual care system from memory alone, which improved to 80% with the use of PAs (p < 0.001). Females were better at recalling care system brand names than males (49% versus 27% correct, p = 0.040) and wearers with more than 1 year experience with their habitual CLs had better recall than those with up to 1 year experience (63% versus 27%, p = 0.014).

Conclusion

Less than 50% of contact lens wearers were able to recall the names of their habitual lens and lens care products correctly from memory. PAs improved this recall significantly for both contact lenses and contact lens care systems.     

Quarter of a century of contact lens prescribing trends in the United Kingdom (1996 – 2020)

PurposeTo document contact lens prescribing trends in the United Kingdom over the past quarter of a century.MethodsAn annual survey of contact lens prescribing was conducted each year from 1996 to 2020, inclusive, by asking a random selection of optometrists and contact lens opticians to provide information relating to 10 consecutive contact lens fits between January and March.ResultsOver the 25 year survey period, 2,671 practitioners returned survey forms, reporting a total of 25,575 contact lens fits. The mean (± standard deviation) age of lens wearers was 35 ± 15 years, of which 64 % were female. Over the survey period, rigid lens new fits decreased from 22 % to 2%. The prescribing of silicone hydrogel lenses has increased steadily since their introduction towards the end of the 1990s, and now represent 80 % of soft lens fits. Soft toric lens prescribing has gradually increased to 47 % – a value at which astigmatism ≥ 0.75DC is theoretically corrected in all contact lens wearers. Daily disposable prescribing increased steadily over the survey period and now represents 63 % of lenses prescribed. Extended wear fits remain at very low levels, except for some prescribing for overnight orthokeratology. Multi-purpose lens care solutions are ubiquitous; peroxide and other systems are now seldom prescribed. Rigid lenses and monthly replacement soft lenses are predominantly worn on a full time basis, whereas daily disposable soft lenses are mainly worn part time.ConclusionsThis report documents the evolution of contact lens fitting in the United Kingdom over the past 25 years. The most likely lens fit is a spherical design silicone hydrogel daily disposable contact lens prescribed for a 35 year old female and worn on a part-time basis.     

International survey of orthokeratology contact lens fitting

Purpose. To determine the extent of orthokeratology (OK) contact lens fitting worldwide and to characterize associated demographics and fitting patterns.Methods. Survey forms were sent to contact lens fitters in 45 countries between January and March every year for 14 consecutive years (2004 – 2017, inclusive). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form.Results. Data were obtained for 295,044 contact lens fits, of which 2,702 were with OK lenses and 292,342 were with other lens types (non-OK). Overall, OK lenses represented 1.2% of all contact lens fits, with significant differences between nations (p < 0.0001), ranging from no fits recorded in Brazil, Egypt, Indonesia, Iran, Lithuania, Nepal and the United Arab Emirates, to 6.0% in The Netherlands. There has been a slight overall increase in OK lens fitting over the survey period (p < 0.0001). OK lenses were fitted to younger persons (OK, 25.0 ± 12.8 years vs. non-OK, 39.8 ± 14.9 years) (p < 0.0001). A higher proportion of males (55%) were fitted with OK lenses versus non-OK lenses (30%) (p < 0.0009). There was a skewed distribution towards OK lenses being fit with higher oxygen permeable materials (p < 0.0001) and on a planned replacement basis (p < 0.0001).Conclusions. OK contact lens prescribing is a niche activity, with this lens type typically being fitted in high oxygen permeable materials on a planned replacement basis to younger males. The slightly increasing rate of OK fitting, albeit at a very low level, may be attributed to practitioner interest in the reported myopia control properties of this lens type.     

International survey of contact lens fitting for myopia control in children

PurposeTo determine the extent of contact lens fitting for myopia control (MC) in children (defined as ≤ 17 years of age) worldwide and to characterize the associated demographics and fitting patterns.MethodsSurvey forms were sent to contact lens fitters in 66 countries between January and March every year for eight consecutive years (2011–2018, inclusive). Practitioners were asked to record data relating to the first 10 contact lens fits performed after receiving the survey form. Data were analysed for those countries reporting ≥ 100 contact lens fits to children.ResultsData were analysed for 535 MC fits and 23,295 other (non-MC) lens fits undertaken in 31 countries reporting ≥ 100 contact lens fits to children, with 52.1% of MC fits and 12.0% of non-MC fits being with rigid lenses (p < 0.0001). Overall, MC lenses represented 2.3% of all contact lens fits to children, with significant differences between nations (p < 0.0001), ranging from no MC fits recorded in the Czech Republic, Greece, Japan, South Korea and Puerto Rico, to 24.9% in Austria. There has been an increase in contact lens fitting for MC over the survey period (p < 0.0001). MC contact lenses were fitted to younger children compared to non-MC lenses (MC, median 13 years vs. non-MC, median 15 years) (p < 0.0001). There was no sex bias in the fitting of MC lenses (p = 0.89).ConclusionsMC lenses are currently being prescribed for younger children in equal measure in terms of soft vs. rigid lenses and males vs. females. The extent of MC fitting is low and varies between nations. The gradual increase in MC fitting throughout the survey period perhaps reflects growing concerns among practitioners over the myopia epidemic.     

Multi-centre evaluation of two daily disposable contact lenses.

PURPOSE: To evaluate the clinical performance of two daily disposable contact lenses: 1-DAY ACUVUE (1DA) (etafilcon A, Johnson & Johnson Vision Care) and FOCUS DAILIES with AquaComfort (FD) (nelfilcon A, CIBA Vision, Inc.), which contains a quickly released moisture enhancing agent, polyvinyl alcohol (PVA). METHODS: This was a 1-week, daily wear, subject-masked, bilateral, parallel group study with subjects randomly assigned to one of two daily disposable soft contact lenses. Subjects were existing soft contact lens wearers in the age range 18-39 years with a spherical refraction between -0.50 and -6.00 D. Subjects were assessed at baseline and after 1 week. Assessments included both subjective (symptoms, wearing time, vision) and objective (lens fit and ocular health) outcomes. RESULTS: Twenty clinical sites enrolled 282 subjects (74% female) of whom 276 (98%) successfully completed the study. Significantly more 1DA wearers reported higher mean comfort scores than with FD (3.95 versus 3.41, respectively, P<0.0001). End-of-day comfort means were also significantly higher with the 1DA group compared to the FD group (3.3 versus 3.0, P=0.03). The 1DA group reported significantly longer mean overall wearing time (1DA was worn on average 0.66+/-0.30 h longer than FD, P=0.03) and longer mean comfortable wearing time (1DA was worn on average 1.73+/-0.35 h longer than FD, P<0.0001). The 1DA lens generally showed significantly better on-eye fitting in terms of movement in primary (P<0.0001) and upgaze (P<0.0001) and ease of removal from the eye (92% versus 63%, P<0.0001) compared to FD. There was significantly less corneal staining observed with the 1DA wearing eyes compared with the FD wearing eyes (23% versus 45%, respectively, P<0.0001). Finally, there was a weak correlation between corneal staining and comfort for FD (r=0.27, P=0.002, n=136), but not for 1DA (r=-0.11, P=0.18, n=140). CONCLUSION: Subjective and objective clinical performance differences between two commonly used daily disposable lenses highlight that, although both lenses may be considered as clinically acceptable, these lenses should not be regarded as interchangeable.     

Efficacy of spherical aberration correction based on contact lens power

PurposeTo investigate the efficacy of spherical aberration (SA) correction with aspheric contact lenses (aspheric lenses) based on lens power, and compare the results with those of spherical contact lenses (spherical lenses).MethodsOcular higher-order aberrations were measured with a wavefront sensor, in 11 myopic subjects wearing an aspheric lens (Medalist Fresh fit (PUREVISION 2 HD); Bausch + Lomb) or a spherical lens (ACUVUE Oasys; Johnson & Johnson). Six different lens powers (−7.00 diopters (D), −5.00 D, −3.00 D, −1.00 D, +1.00 D, +3.00 D) were used for all subjects. The amount of SA correction from the contact lens at each power was calculated as the difference between SA with the contact lens on-eye and SA of the eye alone.ResultsFor the spherical lenses, SA correction was close to 0.00 μm for the +1.00 D lens, became more positive as the labeled lens power increased and became more negative as the labeled lens power decreased. For the aspheric lenses, SA correction was consistent, from −0.15 to −0.05 μm, for all lens powers except for the −1.00 D lens. SA correction for the spherical and aspheric lenses was significantly different at −7.00 D (p = 0.040), −3.00 D (p = 0.015), −1.00 D (p < 0.001), +1.00 D (p = 0.006), and +3.00 D (p < 0.001) powers.ConclusionAn aspheric lens is capable of correcting SA at different lens powers, and has SA correction in the range of −0.15 to −0.05 μm over a 6 mm aperture.