Evaluation of the Effectiveness of the Super Enhanced Single Vision Lens L01 (SESL01) in Reducing Symptoms of Computer Vision Syndrome (CVS): a Double-blind Two-arm Parallel Randomised Controlled Trial
Phase: NA
Conditions: Computer Vision Syndrome
Sponsor: University of Central Lancashire

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TITLE:  Evaluation of the effectiveness of the Super Enhanced Single Vision Lens L01 (SESL01) 
in reducing symptoms of Computer Vision Syndrome (CVS): a double-blind two-arm parallel 
randomised controlled trial 
 
ACRONYM:  
SESL01-Trial 
 
Protocol version: 
 
10.0 
Date:   
 
 
28.04.2022 
 
 
 
Reviewed version 
 
 
Date:   
 
 
 
 
IRAS project ID: 310361 
 
 
 
Trial registration  
 
TBC 
 
Study design Double-blind two-arm parallel randomised controlled trial 
 
 
Funding and support Carl Zeiss Vision International GmbH c/o; Carl Zeiss Vision UK Ltd 
 
 
 
 
 
Project CODE  
 
 
 
 
Confidentiality  
This document contains confidential information that must not be 
disclosed to anyone other than the Sponsor, the Investigators Team, host organisation(s), and 
the Research Ethics Committee members unless authorised to do so.  
 
 
 
 

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Contents 
KEY STUDY CONTACTS ............................................................................................................................ 4 
Study summary ....................................................................................................................................... 4 
FUNDING AND SUPPORT IN KIND ........................................................................................................... 5 
ROLE OF STUDY SPONSOR AND FUNDER ................................................................................................ 5 
Background ............................................................................................................................................. 7 
What is the problem to be addressed? .............................................................................................. 7 
What is Computer Vision Syndrome? ................................................................................................. 7 
Management of Computer Vision Syndrome ..................................................................................... 8 
Aim .......................................................................................................................................................... 8 
Key research questions ........................................................................................................................... 8 
Trial Design .............................................................................................................................................. 8 
Methods .................................................................................................................................................. 9 
Study setting ....................................................................................................................................... 9 
Participants eligibility criteria ............................................................................................................. 9 
Intervention ...................................................................................................................................... 10 
Criteria for discontinuing or modifying allocated interventions ...................................................... 13 
Strategies for monitoring and improving protocol adherence ......................................................... 13 
Research instrument ......................................................................................................................... 13 
Outcomes .......................................................................................................................................... 14 
Sample size ........................................................................................................................................ 14 
Recruitment ...................................................................................................................................... 14 
Clinician-patient ratio ....................................................................................................................... 15 
Randomisation, sequence generation, allocation, and blinding ...................................................... 15 
Data collection .................................................................................................................................. 16 
Data management ............................................................................................................................ 16 
Statistical methods............................................................................................................................ 16 
Primary outcome .............................................................................................................................. 16 
Secondary outcomes ......................................................................................................................... 16 
Secondary analysis ............................................................................................................................ 16 
Data monitoring ................................................................................................................................ 17 
Risk and safety issues ........................................................................................................................ 17 
Harm ................................................................................................................................................. 17 
Process for dealing with a case of spectacle non-tolerance. ............................................................ 18 

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Auditing ............................................................................................................................................. 18 
Research and dissemination ............................................................................................................. 19 
Regulatory approvals ........................................................................................................................ 19 
Protocol amendments ...................................................................................................................... 19 
Consent, invitation, and confidentiality ............................................................................................ 19 
Declaration of interest ...................................................................................................................... 20 
Dissemination policy ......................................................................................................................... 20 
Ancillary post-trial care ..................................................................................................................... 20 
Patient and public involvement ........................................................................................................ 20 
Funding ............................................................................................................................................. 20 
Acknowledgements ........................................................................................................................... 20 
Author contributions ........................................................................................................................ 21 
References ........................................................................................................................................ 22 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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KEY STUDY CONTACTS 
Chief Investigator 
 Andrea Manfrin 
Principal investigator 
Rupal 
Lovell-Patel 
(RLovell-
Patel@uclan.ac.uk) 
Sponsor 
Zeiss Vision Care, UK 
Funder(s) 
Zeiss Vision Care, UK 
Key Protocol contributors 
Rupal Lovell-Patel, Izabella Penier, Miland 
Joshi, Andrea Manfrin 
 
Study summary 
Study title 
Evaluation of the effectiveness of the Super 
Enhanced Single Vision Lens L01 (SESL01) in 
reducing symptoms of the Computer Vision 
Syndrome (CVS): a double-blind two-arm 
parallel randomised controlled trial 
Internal ref.no. (or short title) 
 SESL01-Trial 
Study design 
A double-blind two-arm parallel randomised 
controlled trial 
Study participants 
Patients 
Planned size of Sample 
300 patients 
Planned study Period 
June-September 
Research Questions/Aim(s) 
Research questions: Is the Super Enhanced 
Single Vision Lens 01 (SESL01) effective in  
I. 
Reducing symptoms of the Computer 
Vision Syndrome (CVS), compared with 
standard single vision lenses, assessed 
by the Computer Vision Syndrome 
Questionnaire (CVS-Q®) scores? 
II. 
Improving the near visual performance 
when using digital devices, compared 

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with standard single vision lenses, 
assessed by clinical measurement of 
accommodative 
facility 
using 
the 
standard ± 2.00 dioptre spherical lens 
flippers, measured as cycles per minute. 
 
Aim: To evaluate the effectiveness and 
safety of the SESL01 in reducing symptoms 
of the Computer Vision Syndrome. 
 
FUNDING AND SUPPORT IN KIND 
FUNDER(S) 
Carl Zeiss Vision International GmbH c/o Carl 
Zeiss Vision UK Ltd 
 
ROLE OF STUDY SPONSOR AND FUNDER  
The sponsor, Carl Zeiss Vision International GmbH c/o Carl Zeiss Vision UK Ltd, takes on overall 
responsibility for proportionate, effective arrangements being in place to set up, run and 
report a research project 
Study coordination  
Rupal Lovel-Patel, the Principal investigator (PI), will be responsible for the research site under 
the Chief investigator's supervision. 
 
 
 
 
 
 
 
 
 
 

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LAY SUMMARY  
The increased use of digital devices such as computers, smartphones, tablets, and laptops has 
transformed how people learn and work and has increased the use of screens. This has 
created visual challenges for some users, such as maintaining a clear vision for a long period 
even when looking at different devices. Consequently, digital device users can experience eye 
problems such as blurred vision, eye strain, headaches, and dry eyes. Such problems are more 
common in people aged 21-45, and it seems that the COVID-19 pandemic has worsened them. 
Studies suggest that using specially designed spectacle lenses could reduce these problems. 
Therefore, we aim to study whether specially designed spectacle lenses are more effective 
than standard ones in minimising these problems. The study will be conducted at the 
University of Central Lancashire at the Preston campus (UK). We will recruit 300 patients 
divided into two equal groups. Patients in group A will receive spectacles with special lenses 
while group B will receive spectacles with standard lenses. These two groups of patients will 
be assessed three times, at 4-week intervals, and the final analysis will be performed at 14 
weeks. The reduction of the eye problems will be assessed using a validated questionnaire 
which will produce a score that will be compared between the two groups at the end of the 
study. The study will start in June and end in September.  
The study’s potential benefits are twofold:  
1) Patients using the new lenses will hopefully see a reduction in eye problems 
2) Opticians will provide be able to provide better patient care.  
 
Carl Zeiss Vision International GmbH c/o (Carl Zeiss Vision UK Ltd) has funded the study. In 
addition to free eye examinations and spectacles, participants will receive £60 Amazon 
vouchers at the end of the study as compensation for their time and costs incurred to 
participate in the study. All participants will need to return the spectacles supplied as part of 
this study so that they can be reglazed with standard lenses. All participants will be able to 
use their Zeiss spectacles with standard lenses after the study is complete. 
 
 
 
 
 
 
 
 

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Evaluation of the effectiveness of the Super Enhanced Single Vision 
Lens 01 (SESL01) in reducing symptoms of Computer Vision 
Syndrome (CVS): a double-blind, two-arm parallel randomised 
controlled trial 
Background 
What is the problem to be addressed? 
In the last two decades, the way people acquire information has changed dramatically [1-2]. 
During that time, engagement with digital devices in developed countries has increased 
significantly, particularly in the field of mobile media [3]. The increasing use of digital devices 
showed implications for health, eyes, and vision. A European study found out that by the age 
of 3, 68% of children regularly use a computer and 54% undertake online activities [4]. In 
2016, it was estimated that UK adults typically spend almost 5 hours a day using digital 
media, with a similar pattern developing in the USA [5]. The use of digital devices has caused 
Computer Vision Syndrome (CVS), also called Digital Eye Strain (DES) or Visual Fatigue (VF), 
which has been well described in the literature for over 20 years [6-10].  
What is Computer Vision Syndrome? 
The American Optometric Association defines Computer Vision Syndrome (CVS) as a group of 
eye and vision-related problems resulting from prolonged exposure to digital/computer 
devices [11]. CVS has been linked to using a variety of digital devices [10] such as 
computer/laptop screens, tablets, and smartphones, which has been steadily growing [11]. 
The most common symptoms are eye strain, tired eyes, irritation, burning sensation, redness, 
blurred vision, and double vision [8]. Therefore, a person using digital devices and 
complaining about one or more of those symptoms might be suffering from CVS. 
Furthermore, CVS could cause non-ocular symptoms such as headaches and pain in the 
shoulders, neck, and/or back. Blehm et al. [9] identified four CVS categories. The first is 
asthenopia: eye strain, tired eyes, sores, and dry eyes. The second is ocular and related to eye 
surface: watery eyes, irritated eyes, contact lens problems. The third is the visual category: 
blurred vision and slowness of focus. The fourth category is extraocular and is represented by 
neck, shoulder, and back pain. 
CVS symptoms result in poorer visual performance, and even though they are transient, they 
occur frequently and cause considerable discomfort for sufferers. CVS lowers productivity 
(increased errors and more frequent breaks) and impinges on job satisfaction and quality of 
life [12]. Millions of individuals of all ages are at risk of CVS, and according to different studies, 
the prevalence of CVS ranges from 25% to 93%, depending on the cohort of the studied 
population, the definition and methodology employed to measure CVS [6]. These results 
indicate that a large proportion of the population may need treatment for CVS.  

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CVS affects all age groups, including older age groups (aged 65+), in which the use of 
technology is also rapidly growing [13]. However, the most affected population are younger 
users, who are more likely to simultaneously use two or more digital devices. For example, 
recent US data indicates that while adults aged 60 years and over prefer using laptops and 
desktops, younger adults are more likely to use smartphones too [5]. Since they use digital 
devices for work and social purposes (e.g. social media), they often multitask and switch 
between different devices.  
The COVID-19 pandemic introduced homeworking and remote learning and further increased 
exposure to digital screens. Moreover, lockdowns increased unhealthy digital recreational 
activities, with people turning to television and social media for entertainment [18].  
Management of Computer Vision Syndrome 
CVS management includes correction of refractive error and/or presbyopia (long-sightedness 
caused by loss of elasticity of the lens of the eye, occurring typically in middle and old age; 
managed by prescribing a ‘near add’), dry eye management, regular screen breaks, and eye 
exercises for vergence and accommodative problems (such as a lag in changing the focus from 
near to far distance) [6]. Some studies [6] have explored the role of blue light-filtering 
spectacle lenses with mixed results, indicating that blue light-filters may not alleviate 
symptoms of CVS. Given the high prevalence of CVS and near-universal use of digital devices, 
it is essential that eye care practitioners can provide advice and management options that are 
evidence based.  
Aim 
To evaluate the effectiveness and safety of the Super Enhanced Single Vision Lens 01 (SESL01) 
in reducing symptoms of Computer Vision Syndrome. 
Key research questions 
The key research questions of this study are: 
Is the SESL01 lens effective in  
I. 
Reducing the symptoms of the CVS compared with standard single vision lenses, 
assessed by the Computer Vision Syndrome Questionnaire (CVS-Q®) scores? 
III. 
Improving near visual performance when using digital devices, compared with 
standard single vision lenses, assessed by clinical measurement of accommodative 
facility using the standard ± 2.00 dioptre spherical lens flippers, measured as cycles 
per minute? 
Trial Design 
It is a double-blind two-arm parallel randomised control trial that aims to evaluate the 
effectiveness of SESL01 in CVS management. The study will mimic the routine optometric 

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practice, except that patients will be randomly allocated to the intervention or control groups. 
The patient's follow-up period is 14-week from the baseline. 
Methods 
Study setting 
The study will be conducted at the University of Central Lancashire on the Preston campus in 
the UK. 
Participants eligibility criteria 
Inclusion criteria: 
I. 
Able to provide informed consent 
II. 
21-45 years of age 
III. 
Adults diagnosed with CVS: CSV-Q score ≥6 
IV. 
Participants WITH AND WITHOUT refractive error are acceptable BUT none should 
have 
previously 
worn 
a 
“near 
add” 
correction 
(e.g. 
no 
previous 
bifocal/varifocal/enhanced single vision lens [ESL] wear) 
V. 
Range of refractive errors should be no more than +4.00 to -6.00 dioptric spherical 
power (DS) and +2.00 dioptric cylindrical power (DC) 
VI. 
Must use digital devices for work and/or leisure for at least 1 hour per day (this 
includes smartphones, tablets, and laptops but EXCLUDES PC-only users) 
VII. 
Patients MUST have visual symptoms associated with digital device use, e.g. one or 
more of the following symptoms: 
a. Tired eyes 
b. Eye strain 
c. Blurred vision 
d. Frontal headaches 
e. Difficulties keeping clear vision when changing focus from near to distance 
f. Difficulties keeping clear vision when changing focus from one device to 
another 
Exclusion Criteria: 
I. 
Lack of capacity to provide informed consent.  
II. 
Amblyopia 
III. 
Pregnancy 
IV. 
Diagnosed dry eye disease 

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V. 
If a patient develops dry eye symptoms or is diagnosed at follow-up appointments, 
treatment will be started and assessed in two weeks.  
VI. 
On anti-depressants (or other medication that can affect accommodation, such as 
reduced focusing power) 
VII. 
Any diagnosed ocular pathology (such as glaucoma, corneal dystrophies, lid disorders, 
and retinal pathologies) 
VIII. 
Change in ±0.75DS/DC in the spectacle prescription [15-20].  
Intervention 
Participants in the intervention group will wear the newly designed SESL01 lens. The SESL01 
is an Enhanced Single Vision Lens design. Enhanced Single Vision Lenses (ESL) have a small 
amount of positive power towards the bottom of the lens, as this is the area that is in line 
with the eye when looking downwards for near tasks. The small amount of positive power is 
expected to reduce the effort by the eyes to maintain a clear, in-focus image when looking at 
tasks at near. 
Patients in the control group will be corrected with standard single vision lenses with an anti-
reflection coating.  
Both patient groups will have a choice of spectacle frames (within a set price range of up to 
£70) to select for their new spectacle correction. At the end of the study, all spectacles will be 
returned to the research team so that they can be reglazed with standard single vision lenses 
with an anti-reflection coating ensuring that the intervention lens (SESL01) is not in the public 
domain ahead of its official release. 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Table 1 Schedule of enrolment, intervention, and assessments 
 
Near Visual Performance (NVP) includes all the assessments (variables) listed after the CVS-Q 
 
 
 
Enrolment  
Screening
Allocation 
Baseline
Spectacle 
collection
Closeout
Timepoint (weeks)
-W0
W0 
W2
W6
W10
W14
Enrolment
Eligibility screen for patients
x
Informed consent for patients
x
Randomisation for patients
x
Spectacles collection
x
Intervention Group will use the Super Enhanced Single
Vision Lens L01 (SESL01)
x
x
x
x
Control Group will use the standard single vision lenses
x
x
x
x
Assessments 
 
Computer Vision Syndrome Questionnaire (CVS-Q)
x
x
x
x
x
LogMAR Vision and Visual Acuity (using a computerised
chart: 6/6 minimum monocular distance VA and N6
monocular)
x
x
x
x
Non-cycloplegic
refractive
error
assessment
(anisometropia of ≤1.50DS in any one meridian, +4.00 to -
6.00DS and +2.00DC)
x
Cover test (D&N)
x
Ocular Motility
x
Pupil size (D&N)
x
Fixation Disparity (D&N)
x
Monocular and binocular amplitude of accommodation
x
x
x
x
Near point of convergence
x
x
x
x
Slit lamp Assessment (including measuring of tear break-
up time, less than 11sec is an exclusion criteria)
x
Indirect assessment of the fundus (Volk)
x
Optical Coherence Tomography imaging
x
Intra-Ocular Pressure measurements for those aged
40yrs and over
x
Visual Fields
x
Wilkins Rate of Reading
x
x
x
x
Accommodative Facility in cycles per
minute (with
spherical lens flippers and Zeiss own brand app)
x
x
x
x
Thomson Clinical Eye Tracking (with blink rate)
x
x
x
x
Study period
Post-allocation

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Figure 1 CONSORT flow diagram 
 
 
 
CVS-Q: Computer Vision Syndrome Questionnaire;  NVP: Near Visual Performance  
 
 
 

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 Criteria for discontinuing or modifying allocated interventions 
i. Participant withdraws consent 
ii. The trial is discontinued 
iii. Participant requires hospitalisation or out-patient ocular surgical treatment 
The reasons for discontinuation will be documented. Participants will be invited to participate 
in an outcome-related assessment to determine the effectiveness of the intervention. 
Participants will be asked to return the spectacles provided for the study. 
Strategies for monitoring and improving protocol adherence 
There are some measures that clinicians could adopt to improve patient adherence to the 
research protocol, such as telephone calls, text reminders, and social support to educate 
patients on using their spectacles. In addition, clinicians will have to create a welcoming, non-
judgmental, and accepting environment; educate patients about their role as research 
participants; establish a routine while maintaining flexibility; provide incentives for 
participation, such as Amazon vouchers, parking spaces, and video consultations.  
Research instrument 
The CVS will be assessed using the CVS Questionnaire (CVS-Q) developed by Seguí et al.’ [21]. 
The CVS-Q has questions on 16 ocular and visual related symptoms which will be presented 
to the patients. These symptoms are burning, itching, feeling of a foreign body in the eye, 
tearing, excessive blinking, eye redness, eye pain, heavy eyelids, dryness, blurred vision, 
double vision, difficulty in focusing on near objects, increased sensitivity to light, coloured 
halos around objects, feeling that sight is worsening, and headache. The frequency of these 
symptoms is defined based on how often they occur: sometimes or occasionally, once per 
week, always or often if they occur two to three times per week or every day [7]. The intensity 
of the symptoms is scored as never=0, mild to moderate=1, severe=2. To measure the 
frequency of the symptoms, patients will be asked to choose the following options for each 
of them: never=0, sometimes or occasionally=1, always or often=2. 
The following formula will be used to calculate the total score 
 
Seguí et al. [17] suggested that a good balance between sensitivity and specificity is 
represented by a cut-off value of 6 for the total CVS-Q score. Therefore, patients with a CVS-
Q total score ≥6 are suffering from CVS and will be included in the study. In the absence of a 
universal consensus on CVS severity grading, Alhasan et al. [24] adopted the following criteria: 
participants with a total score of 6-12 were deemed to have mild CVS, those with a score of 
13-19 moderate, and those with a score ≥20 were considered to have severe CVS.  
i
16
1
i
i
symptom)
 
of
 
(intensity
x 
 
)
occurrence
 
symptom
 
of
 
(frequency
Score ∑
=
=

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Outcomes 
Primary outcome 
The primary outcome measure is the effectiveness of the SESL01 in reducing the CVS 
compared with standard single vision lenses, assessed using the CVS-Q® scores at week 14. 
Secondary outcome 
The secondary outcome is the effectiveness of SESL01 compared with standard single vision 
lenses in improving the near visual performance when using digital devices assessed by 
clinical measurement of accommodative facility in cycles per minute using spherical lens 
flippers as well as optometric tests such as near LogMAR visual acuity, amplitude of 
accommodation, near point of convergence and rate of reading. 
In addition to performance of the lens in terms of reducing CVS and improving near vision 
function, the study will consider the safety of the lens before it can be prescribed safely to 
the wider population. 
Sample size 
Seguí-Crespo et al. [20] and Alhasan et al. [24] suggested that the CVS-Q score is not normally 
distributed. Alghamdi and Alrasheed [23] and Sanchez Brau et al. [25] summarised their 
findings using means and a wide range of standard. Therefore, in our study it was decided to 
conduct the power calculation using a standard deviation of 3.5, which is within the 1.8-6 
range. We also assumed an initial normal distribution in the arms with expected means of 8 
in the control and 6 in experimental groups. We then estimated the power for different 
sample sizes by simulation, truncating the values generated to select those at least 6. The 
result was that a sample size of 150 per group would give us a power of 80% to detect the 
clinically important difference of 2, even allowing for a dropout of 10%. Therefore, with a 1:1 
allocation and sample size of 300 patients (150 in the intervention group [IG] and 150 in the 
control group [CG]), we expect there to be sufficient power to detect this effect size. 
 
Recruitment 
Recruitment will be focussed mainly on students and staff within the University of Central 
Lancashire.  
Student recruitment: Announcements on the virtual learning platform (the Blackboard) will 
be used along with posters around the campus with the details of the study. Project invites 
can be sent out via Social Media accounts and student email addresses. The university has a 
large portion of mature students, so recruiting patients within the required age range will be 
possible. 
Staff recruitment: Emails, announcements on internal comms, social media accounts, work 
email addresses, and posters will be used to encourage colleagues to participate. 

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Recruitment will start as soon as University ethics and NHS REC approval have been granted 
and the sponsor has opened the study site. 
The recruitment strategy will increase potential participants’ awareness of the health 
problem being studied, its potential impact on their health, and engagement in the learning 
and training of healthcare professionals. 
Clinician-patient ratio 
For eye test and clinical measurements, the ratio of participants to clinicians is 150:1 but each 
interaction/data collection appointment will be on a 1:1 basis. 
For spectacle frame selection and measurements, the ratio is 300:1; however, each 
interaction will be on a 1:1 basis.  
Randomisation, sequence generation, allocation, and blinding 
Randomisation 
An academic from UCLan, who is an expert in the use of statistics, will oversee the 
randomisation process. The total number of patients (n=300; IG=150, CG=150) will be 
randomised with a 1:1 ratio using permutated block randomisation. The groups will have 
equal sizes and will tend to be uniformly distributed by key-outcome-related characteristics 
[18]. 
Unit of randomisation and intervention  
The patient is the unit of randomisation and intervention. 
Block size 
Blocked randomisation will provide a balance between study arms, reducing the opportunity 
for bias and confounding. The block size in this study will be two and four [19].  
Sequence generation 
The sequence generation will be conducted using randomisation with block permutation 
without stratification.  
The block permutation, randomisation, and sequence generation will be performed using 
PASS (Power Analysis and Sample Size Software) 2021, (NCSS, LLC. Kaysville, Utah, USA, 
ncss.com/software/pass). 
Allocation concealment 
The procedure adopted in this study for assuring the allocation concealment will be the use 
of sequentially numbered, opaque, and sealed envelopes (SNOSE).  
Blinding 
In our study, the clinicians (opticians) performing the assessment and follow-up and the 
patients receiving and wearing the spectacles will be blinded to the treatment.  

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Data collection 
Clinicians will collect data at baseline and 4-week intervals using paper questionnaires. 
Data management 
Data will be managed following the procedure used in a previous study [20]. Input data will 
be saved and stored on a password-protected system. Only individuals authorised by the CI 
will be allowed to access the data. Paper data, such as clinicians’ informed consent, will be 
kept in a locked cabinet by the research team. Patients’ informed consent will be kept by the 
clinicians in a locked cabinet. 
Statistical methods 
The primary analysis will be the intention-to-treat (ITT), including all randomised participants 
in the group where they were randomly assigned, regardless of their adherence to the 
protocol or their withdrawal.  
Missing data will be assessed and treated using multiple imputation of missing at random 
(MAR).  
To check for normality, each variable will be analysed using the Kolmogorov-Smirnov and 
Shapiro Wilk tests. 
Primary outcome 
The primary outcome measure (CVS-Q score) will be assessed at week 14 using an unpaired 
analysis. The analysis will be performed without adjustments; then, it will be adjusted using 
the baseline CVS-Q scores, age, and gender and the CVS-Q at 6 and 10 weeks using generalized 
estimating equations (GEE), which is a semiparametric technique useful for repeated 
measures that work for dichotomous and continuous data, as in our case.  
Secondary outcomes  
The secondary outcome measure, the improvement of the near visual performance when 
using digital devices using SESL01 compared with standard single vision lenses will be assessed 
using the clinical measurement of accommodative facility in cycles per minute using spherical 
lens flippers at week 14 as well as optometric tests such as near LogMAR visual acuity, 
amplitude of accommodation, near point of convergence and rate of reading.  
Secondary analysis 
The secondary analyses will be performed looking at  
• 
the percentage of CVS-Q score <6 (no symptoms) versus CVS-Q score ≥6 (symptoms) in each 
group at 14 weeks. The results will be presented using descriptive statistics at each time point, 
and the differences will be assessed using Pearson’s Chi-square test or Fisher’s exact test and 
odds ratio (OR). 

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• 
The percentage of participants in each group with a total CVS-Q score <6, 6-12, 13-19, and ≥20 
at week 14. The results will be presented using descriptive statistics at each time point, and 
the differences will be assessed using the Mann Whitney U test. 
 
A P-value of ≤0.05 will be considered statistically significant and presented with 95% 
confidence interval where appropriate. The statistical analysis will be performed using SPSS 
(IBM Corp. Released 2021. IBM SPSS Statistics for Windows, Version 28.0. Armonk, NY: IBM 
Corp). 
Data monitoring 
This trial was designed to minimise the risk, as demonstrated in a previous trial [20]. 
Therefore, no formal committee has been organised, and no interim analysis of the impact of 
the intervention has been planned. The is study a monocentric study conducted at the UCLan 
campus in Preston. 
Risk and safety issues 
During this study, there will be no risks for patients. Patients wearing the SESL01 lenses will 
be at no greater risk than those receiving the usual ones. Clinicians will not dispense or 
administer any medications based on the CSV-Q score. In addition, clinicians will not be 
involved in the interpretation of diagnostic tests or their results. 
Covid safety protocols: 
Participants will be required to wear a face covering throughout the examinations while in 
the eye clinic (unless they are exempt). Before the visit, participants will be asked to complete 
a COVID-19 Research Participant Pre-Visit Check Form, which will be used to prevent the 
spread of COVID-19 and to reduce the potential risk of exposure. If participants are displaying 
any COVID symptoms, their data collection appointment will be rescheduled by a week. If 
participants display any COVID-19 symptoms during, or after the visit, the PI should be 
informed, so that the necessary steps can be taken according to relevant government 
guidelines.  
The clinicians in the study will be wearing personal protective equipment, and all equipment 
and room surfaces will be cleaned between participant visits.  
Harm 
We do not expect adverse events or other unintended effects. All information regarding the 
trial will be included in the clinicians’ and patients’ information sheets. 
Spectacle dispensing and prescribing can cause ‘non-tolerance’. Non-tolerance is when a 
participant is not satisfied with their spectacles, which may be due to the lack of clarity of 
vision or discomfort caused by the frames [20]. 
Cases of non-tolerance [15] can be split into: 

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I. 
Dispensing: This is where the fitting of the frame or the dispensing measurements 
were not correct for the participant. 
II. 
Prescription: The participant is not able to adapt to the prescription or there was a 
data entry error, and the incorrect prescription was ordered. 
Cases of non-tolerance are small; research shows that cases in general optometric practice 
range between 1% to 3% [16]. The implication of this data for our study is that approximately 
7 participants may report dissatisfaction with their spectacles. A procedure to handle cases 
of non-tolerance is summarised in Figure 2. 
 
Figure 2 Process for handling non-tolerance
 
Process for dealing with a case of spectacle non-tolerance. 
Should symptoms of non-tolerance remain after the retest for the prescription and re-
dispense, the information will be reported to Carl Zeiss Vision International GmbH c/o Carl 
Zeiss Vision UK Ltd as an adverse effect within 3 working days. Carl Zeiss Vision International 
GmbH c/o Carl Zeiss Vision UK Ltd has an adverse effect reporting template that will be filled 
in and sent to the relevant department within the lens manufacturer. Carl Zeiss Vision 
International GmbH c/o Carl Zeiss Vision UK Ltd will inform MHRA about any adverse effects. 
Auditing 
No audit has been planned at this time. 
Recheck the frame fitting and 
dispensing measurements to 
ensure that the frame is fitting 
comfortably. 
Recheck the prescription in the 
spectacles against the order and the 
actual prescription of the eye test 
record.
Arrange a recheck of 
the 
prescription/retest. 
Redispense the 
spectacles if 
prescription needs 
altering.

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Research and dissemination 
The study protocol and outcomes will be published in peer-review journals, conference 
papers and may be used in training materials for clinicians working in the optical industry. 
Participants will be offered a copy of the final study report submitted to Carl Zeiss Vision 
International GmbH c/o Carl Zeiss Vision UK Ltd. 
Regulatory approvals 
Ethics approval will be sought from and NHS REC, and from the UCLan University REC.  A notice 
of no objection will be sought from the MHRA.  
Protocol amendments 
We are not expecting to make any changes to the eligibility criteria, outcomes, and analyses 
during our study. Any amendments made to the protocol will be submitted to the MHRA 
and/or REC as appropriate.  
Consent, invitation, and confidentiality 
Consent will be obtained according to the International Standards Organisation (ISO) 14155 – 
Clinical investigation of medical devices for human subjects — Good clinical practice 
guidelines. The Chief Investigator (CI) or other qualified member of the study team will make 
the decision as to whether the potential participant is suitable for screening and/or enrolment 
into the study. The potential participant will then be given the patient information leaflet and 
consent form and will have a discussion with the study team member.  
The potential participant will then be given time to consider taking part and take the 
opportunity to discuss the study with others such as friends and family or members of their 
medical team, as applicable and appropriate. Once the potential participant is satisfied that 
they have been fully informed, and they have decided that they wish to enter the study, they 
will be asked by the study team member to sign a consent form.  
The study team member who performs the informed consent discussion will sign the consent 
form. The consent will be confirmed by the personally dated signature of the participant.  
A copy of the signed consent document will be given to the participant and the original signed 
consent will be kept by the study team. The study team will not undertake any measures 
specifically required for the study until valid written consent is obtained. All participants are 
free to withdraw from the study at any time and without giving a reason. A decision to 
withdraw, or a decision not to take part, will not affect the standard of care they receive from 
any institution subsequently. 
The eye test (screening assessment) records will be stored in a locked filing cabinet in the Eye 
Health Clinic and would be uploaded to the UCLan Data Repository within two weeks of 
patients being allocated to a participant group. Anyone who is deemed unsuitable to 
participate will be offered a copy of their eye test record within two weeks and if they do not 

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want their record, it will be shredded in line with the University’s confidential shredding 
procedure. 
Declaration of interest 
None 
Dissemination policy 
The dissemination of the study will begin immediately after the publication of the protocol. 
The results of this trial will be presented at national and international conferences. They will 
be submitted as scientific manuscripts to peer-reviewed journals. The trial results aim to 
inform patients, eyecare professionals and optics students, who would benefit from the 
results.  
The results will be disseminated to service users and their families via media, to healthcare 
professionals via professional training and meetings, and to researchers via conferences and 
publications. 
Ancillary post-trial care 
We are not envisaging the need for the provision of post-trial care. Nevertheless, all 
participants will be provided with an emergency contact number to reach the study 
investigators so that they can receive the necessary support if they have any questions or 
problems. Spectacles provided during the study will be collected so that they can be reglazed 
with standard single vision lenses with anti-reflection coating; the participants may be 
without the new spectacles and will need to wear their own spectacles for a few days. 
Patient and public involvement 
The research protocol was developed during the COVID Omicron wave, December 2021 and 
March 2022; therefore, it was not practical to reach patients and members of the public and 
get their input into the protocol. 
Funding 
The research team is deeply grateful to Carl Zeiss Vision International GmbH c/o Carl Zeiss 
Vision UK Ltd for supporting the research project covering the cost of spectacle frames, 
lenses, and Amazon vouchers. 
Acknowledgements 
The research team wants to thank Dr Navneet Gupta for his support as the liaison between 
the research team at UCLan and Carl Zeiss Vision International GmbH c/o Carl Zeiss Vision UK 
Ltd.  
In preparation of this protocol, Dr Miland Joshi acted as a critical friend for the development 
of the statistical analysis plan, so the research team would like to acknowledge this support. 

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Author contributions 
Conceptualisation: Rupal Lovell-Patel and Andrea Manfrin 
Data curation: Andrea Manfrin 
Formal analysis: Andrea Manfrin 
Funding acquisition: Rupal Lovell-Patel 
Methodology: Andrea Manfrin and Rupal Lovell-Patel 
Project administration: Rupal Lovell-Patel  
Visualisation: Rupal Lovell-Patel, Izabella Penier, Andrea Manfrin 
Writing – original draft: Rupal Lovell-Patel, Andrea Manfrin 
Writing – review & editing: Izabella Penier 
 
 

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