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Abstract
In 1888, Adolf Fick successfully fit contact lenses, which were made from blown glass to
human. Since then, contact lenses have undergone development and revolution until this
very day. To use contact lenses, a person is required to acquire basic knowledge of handling
contact lenses. Many studies in the past are more towards the treatment and prevention of
conditions resulting from contact lens contamination and colonization by foreign organisms.
Therefore, the aim of our research is to study the effect maintenance of contact lenses
towards users’ health. The medium of our research are survey conducted towards identified
UTP student who are using contact lenses. The results of our survey found that a number of
respondents did not practice the proper way in maintaining their contact lenses. We
concluded that improper maintenance of contact lenses would affect users’ health. However,
due to the certain limitation, we suggest that another study in would be conducted with larger
number of respondent in future. We would also suggest that research in the future to focus
more on type of solutions used by contact lens users as we could not find any significant
evidence to prove whether or not it affect users’ health.
Contents
1. Abstract
2. Introduction
3. Literature Review
4. Methodology
5. Results
6. Discussion
7. Conclusion
8. References
9. Appendix
2. Introduction
The history of contact lens has its root back to 1508 where the idea was inspired by
Leonardo Da Vinci in his journal Codex of the eye, Manual D. He described a technique of
directly altering corneal power by submerging the eye in a bowl of water.
In 1998, an important development was the launch of the first silicone hydrogels onto the
market which has extremely high oxygen permeability with the comfort and clinical
performance of the conventional hydrogels which had been used for the previous 30 years.
A contact lens or also known simply as a contact is a corrective, cosmetic, or therapeutic
lens usually placed on the cornea of the eye. Some soft contact lenses are tinted a faint blue
to make them more visible when immersed in cleaning and storage solutions. Some
cosmetic lenses are deliberately colored to alter the appearance of the eye. Some lenses
now have a UV protection surface treatment to reduce UV damage to the eye's natural lens.
The aim of this study is to investigate whether improper maintenance of contact lenses is the
causes of infection among students in UniversitiTeknologiPetronas (UTP).
Past studies had shown that careless handling of lenses specifically during cleaning of
lenses may lead to microbial infections such as Acanthameoba. This statement had been
claimed by Devonshire, Munro, Abernethy & Clark (1993) and Khalid, Hisham, &Aabed
(2001). Therefore, we would like to study in depth whether the manner of improper cleaning
of lenses could lead to infections or not.
According to Gray, Cursons, Sherwan, &Rose (1995) and Dart (1988), infection does not
only occur on the contact lens itself but can also occur inside the lens case. As lens cases
are only use as storage of lenses, we believed many users have neglected the proper
management of the cases. Here, we would like to investigate the effects of careless
management of lens cases towards contact lens users.
Based on Khalid, Hisham, &Aabed (2001), extended wear of lenses, that is more than one
day could bring harm to the users but Dart (1988) stated in his study that the relation of
period of wearing a lens at one time and the effects on the users depends on the type of the
lenses used. A question is raised here whether prolonged use of lenses could cause harm to
the users or not. We would also investigate this variable in our study.
Our research questions are as follows:
Does improper manner of cleaning contact lenses could lead to infections?
Does careless management of contact lens cases could bring harm to the users and
how frequent should the cases be changed to avoid infections?
What is the optimal period of wearing contact lenses at one time to prevent
infections?
What are the crucial steps in maintaining contact lenses?
In our context of study we define some terms as follow.
Maintenance – ¬includes the act of handling, cleaning, rinsing and storing contact
lenses.
Type of contact lens – categorizing lenses on how long is the contact lens could be
used before disposing. In our study type of contact lenses ranging from daily, weekly,
monthly, and yearly.
Experienced users – Using contact lenses for more than three years.
3. Literature Review
With the rapid advance of technology, the usage of spectacle has been replaced by
just plastic that can be used to correct the eye defects called contact lens or also known as
contacts (Science Daily, n.d., Contact Lens). The idea of contact lens has been introduced
by Leonardo Da Vinci in the year 1508. (Heitz, RF and Enoch, J. M., 1987). Throughout the
years of development, Adolf Fick had successfully came out with the corrective lens in the
year1888 (Pearson R.M., Efron N.,1989). The contact lens made by Fick was using heavy
blown glass. After sometime in the year of 1956 Otto Wichterle invented lenses using soft
hydrophilic gels. But the most important development was the launch of the first silicone
hydrogels onto the market. These new materials encapsulated the benefits of silicone—
which has extremely high oxygen permeability—with the comfort and clinical performance of
the conventional hydrogels which had been used for the previous 30 years.
Why change to lens rather than spectacles.
Our study will mainly focus on the health risk of using contact lenses.We will study
how users manage their lenses to avoid the risk of infection, using contact lenses have been
quite a popular trend around the world as stated by a research by (Barr, 2004),It has been
estimated that 125 million people use contact lenses worldwide (2%), including 28 to 38
million in the United States and 13 million in Japan. The types of lenses used and prescribed
vary markedly among countries, with rigid lenses accounting for over 20% of currently-
prescribed lenses in Japan,the Netherlands and Germany but less than 5% in Scandinavia.
People choose to wear contact lenses often because of their appearances and practicality
(Sokol,Mier,Bloom&Asbell, 2009). Although both glasses and contact lenses have the same
purpose of usage, that is correcting eye sight, however contacts lens have a better
advantage. First and foremost, contact lens are worn right on the eye to create a natural
vision and also creates a wide range of focus compared to glasses which cause distortion as
there is distance between the eye and the glasses that result to poor peripheral or known as
side vision. Contacts lens also do not fog up unlike glasses which do so depending on the
surrounding temperature. Contacts can also match everything in the wardrobe whereas
glasses need to match only certain outfits due to the frames of the
glasses.(http://www.contactlenses.org/clsglasses)
Type of lenses
According to Cornea & Contact Lens Society of New Zealand Inc. (CCLS) (n.d.),
there are 3 types of lenses. The first one is disposable type contact lenses. Disposable
contact lenses are lenses which are designed to be replaced on a regular basis, usually
either daily, two-weekly or monthly. Daily disposable contact lenses are a great option for
people who only want to wear their contact lenses a few times per week, for example, for
sport.
The second type of lenses is the leave-in (extended wear) contact lenses. Leave-in
(extended wear) contact lenses are designed to be worn continuously for 30 days and nights
and then replaced with a new contact lens. They offer the ultimate in convenience, since
they usually don't need removing or mechanically cleaning.
The third type is gas permeable contact lenses. Gas permeable contact lenses are
usually used for the correction of moderate levels of astigmatism. They provide excellent
clarity of vision, especially in cases where the astigmatism is irregular (such as with
keratoconus).
Lenses can also be classifies by their functions (Wikipedia). Corrective contact
lenses are designed to improve vision for those with mismatch between the refractive power
of the eye and the length of the eye, leading to a refraction error. A cosmetic contact lens is
designed to change the appearance of the eye. Food and Drug Administration oh the USA
frequently calls non-corrective cosmetic contact lenses decorative contact lenses. There is
another function which is therapeutic contact lenses. Therapeutic contact lenses are usually
soft lenses and are often used in the treatment and management of non-refractive disorders
of the eye.
The construction materials of contact lenses can also be uses to classify the type of
lenses. (Wikipedia). The first contact lenses were made of glass. The second type are
lenses made from polymethyl methacrylate (PMMA or Perspex/Plexiglas). These PMMA
lenses are commonly referred to as "hard" lenses (this term is not used for other types of
contact lens). Then we have the third type, which is also rigid but were oxygen-permeable.
This type is referred to as rigid gas permeable or 'RGP' materials or lenses. There is also the
next type of contact lenses which are soft lenses. Soft lenses can be further categories into
hydrogels and silicon hydrogels.
How people usually manage their lenses.
For some reasons peoples do not follow meticulously the proper procedure for
wearing contact lenses. Due to the poor management they usually get infections because of
it. This is one of the objectives on this study, to find out how contact lens users managing
their lenses to avoid from getting infections that may lead to serious illness. A study from
Department of Ophthalmology from the New York University Medical Centre showed out of
103 participants of the study, approximately 24% do not clean their lenses and only 5% uses
saline solution as their mode of disinfections. The study also shows that majority of surveyed
either never use enzyme cleaners or only used them less than once a month. About 70% of
patients either never use rewetting drops or only uses them less than once a day. Another
study conducted by ( Matthews, SM, Spallholz, JE, Grimson, MJ , Dubielzig et. Al. 2006)
found contact lenses with covalently attached Selenium molecules have been shown to
reduce bacterial colonization without adversely affecting the cornea of a rabbit eye and
octylglucoside used as a contact lens surfactant significantly decreases bacterial adhesion.
Therefore we can see that with using suitable materials in handling our lens that would
prevent our eyes from getting infections.
Lens cases : on how often they clean it and change it.
Although it may look alike a small matter in caring of the lens but lens cases also play
such important roles in making sure the lens is clean from infections. Besides the fact that
lenses are really sensitive to their environment so the way users care for their lenses can be
one of the main reason why many of them get infections. Our study will raise the point which
is the importance of clean contact lens case. According to the study Compliance and
contamination in lens wear sponsored by Alcon, they found that 36% of contact lens user
wait up until 12 month to change their lens cases where else, 20% were reported they never
clean their lenses and the other 48% cleaned their lens cases with tap water. Another study
sponsored by Johnson & Johnson Vision Care named Making the case for daily disposable
contact lenses: patient non-compliance with storage case hygiene and replacement showed
among 787 contact lens wearers only 30% cleaned their lens case daily; and among these
wearers, 53% cleaned their case with tap water. Also, 4% replaced their case annually or
less often and 7% never cleaned or replaced their lens case. (Most eye care professionals
recommend that lens cases should be cleaned daily with fresh contact lens solution and
allowed to air dry, and lens cases should be discarded and replaced at least every 90 days.
These are some of the bad habits in wearing lenses. Normally users should not wash their
lens cases with tap water because the tap water itself contains a lot of chemical substances
which may infect the lens and contaminate the cases. Plus as the lens case main function is
to store lens and disinfect the lens with the special solution therefore users also need to pay
attention to the cleanliness of the lens cases.
Method of cleaning lenses
Now we have come to the most crucial thing in caring the lenses and this is also the
most important part in our study, on how users clean their lenses. Many cases reported that
wearers had eye problems due to contact lens is not because the lens itself it is because
wearers do not know how to clean their lenses using proper way. A study titled Compliance
and contamination in contact lens wear sponsored by Alcon eye care products producer,
revealed that 71% contact lens users put their lenses directly to the case without rubbing
and rinsing to disinfect them. 11% only rinse them and only 7% performed the recommended
way which is “rinse & rub” cleaning technique. Plus a survey sponsored by CIBA vision
named Compliance with lens care and contact lens case care and replacement surveyed
501 contacts users. The result revealed that 41% of those using multipurpose contact lens
solutions never performed the “rinse & rub” technique. 22% of them “topped off” their case
without discarding old contact lens solution and 26% never cleaned their case. New Zealand
contact lens website have put some guidelines on how to make sure lenses are clean and
safe to wear.
Never wear lenses longer than prescribed. Do not wear daily lenses while sleeping.
Do not wear your lenses overnight unless recommended by your contact lens
practitioner. Overnight wear of contact lenses increases the risk of complications.
Always wash, rinse, and dry your hands before handling lenses. Avoid pump and
moisturising soap and use lint free cotton towels and tissues.
Use only approved contact lens solutions for lubricating or wetting your lenses.
Always use fresh solutions in your lens case when disinfecting your lenses.
Never use non-sterile home-prepared saline. The use of home-prepared saline with
contact lenses has been associated with serious infections.
Contact lens storage cases can be a source of bacteria and other microbial growth.
Lens cases should be cleaned, rinsed, and allowed to air dry each time the lenses
are removed. Replace the lens case frequently. Household bleach is an excellent
disinfectant for contact lens cases but make sure the case is compatible with this and
rinse and dry the case thoroughly.
These are some of the proper way in handling the lenses to make sure that our eyes will free
from the infections, hence avoid us from getting eyes serious illness which some of them
may lead us to be blind.
Proper way of using& Side effects of lenses
For our research, we would also like to know whether the lens wearers in UTP are
practicing the proper way in caring for their lenses. According to Cornea & Contact Lens
Society of New Zealand Inc. (1999-2009) or CCLS, there are few facts that lens wearer
should acknowledge. The organization stated that different solutions should not always be
used together and not all solutions are safe for use with all lenses. They do believed in the
main principle of lens care that lens wearer should only use the lens care solutions
recommended by contact lens practitioner, and do not change brands without first consulting
contact lens practitioner. It is advisable to follow the instructions in the package inserts for
the use of contact lens solutions. This organization has listed down three essential steps in
contact lens care which are (in order) cleaning, rinsing and disinfecting. Contact lenses must
be cleaned, rinsed and disinfected whenever contact lenses are removed. Some solutions
can perform these functions but may not be as effective. The multipurpose solution is the
most popular cleaning solutionfor contact lenses; these are suitable for rinsing, disinfecting,
cleaning and storing lenses, and in most cases eliminate the need for protein removal
enzyme tablets. Every time contact lenses are removed, they must be cleaned, rinsed, and
disinfected before wearing again. Some solutions are designed to perform more than one of
these functions, but may not be as effective.
Fresh solutions should be used, and carrying cases should be boilable or capable of
withstanding pasteurization, It is obvious that boiling or pasteurisation of soft contact lenses
is preferable to making them aseptic by chemical means because of the dangers of solution
contamination. Lenses stored longer than 12 hours require cleaning, rinsing and disinfecting
again before use. However, the weak link in the chain always lies in the handling of lenses
with contaminated fingers; hence instruction in this aspect of the lens care is just as
important as in sterilization methods. Regular cleaning of soft lenses is mandatory,
especially before boiling, to prevent accretion of denatured mucus, protein, and foreign
bodies.
Contact lens wearers and eye care practitioners may rely too much upon contact lens
solutions to reduce microbial contamination. Studies by Ifejika, Borlace, Lucas, Roberts, &
Walker indicates that several multipurpose solutions and peroxide systems are not able to
adequate disinfect concentrations of bacteria. Daily cleaning of contact lenses is not always
properly performed by lens wearers. This indicates that many commercially available lens
care systems may not be adequate on their own. Use of monthly disposable lenses may
encourage less diligence in cleaning lenses. Therefore, an ideal care system needs to
eliminate the qualitative test of “rub and rinse” and substitute a more reliable method for
cleaning contact lenses.
4. Methodology
Overview.
We used a quantitative method of collective data. For that reason, we decided to use the
same method. We conducted a survey to study the effects of improper handling of contact
lenses. The survey was done by distributing questionnaires to contact lens users in UTP.
Population / Sample.
We used selective sampling in conducting the questionnaire. Only the contact lenses users
in UTP were administered the questionnaire. They were varied from foundation to post-
graduate students. We had 40 respondents to answer our questionnaires.
Location
We conducted our survey in UTP which is in Tronoh, Perak. The survey conducted was
easily carried out as we are also studying inUTP. It took us about a week to found 40
respondents. Most of the respondents were found in the UTP information resource center
and Pocket D.
Restriction / Limitations.
Our main restriction during conducting the survey was to identify the contact lens users.
There were not many students in UTP using contact lenses. They are prefer to use
spectacles rather than contact lenses. Moreover we cannot identify if the 40 respondents are
an adequate representation of contact lens users in UTP as we do not know the population
of contact lens user in UTP.
Sampling technique.
We chose to use the selective sampling method in our survey. In this method, we randomly
asked students whether they were contact lens users.
Procedures.
Firstly, we approached these students that most probably were using contact lenses. Only
then the questionnaires were given to them.
Next, respondents were being advised by us on answering the questionnaire. If the
respondent had some enquiries about the questionnaire we will assists them immediately.
The data collected will be kept confidential.
Materials
We used questionnaire as our medium to collect information on our studies. There are 2
types question open ended and multiple choice questions. Refer to Appendix A.
5. Results
Figure 1.1 showed the user’s period of using contact lenses. There were 30% users wore
contact lenses more than 3 years and less than 1 years. There were 20% wore contact
lenses for 1-2 years and 2-3 years.
Figure 1.2 above showed the percentage of respondents on their purpose of wearing contact
lenses. There were 7% wore contact lenses for cosmetic purpose, and 38% for corrective
purpose. The remaining 55% wore contact lenses for both purposes.
Figure 1.3 showed that the most likely type of lenses used was monthly by 83%, followed by
daily disposable lenses by 10%. Yearly and weekly type of lenses are 4% and 3%
respectively.
Figure 1.4 showed the users tend to change their lens case once per month by 53%, both for
yearly and others are 17%. 10 % changed their lens case every day and 3% changed it once
a week.
Figure 1.5 showed type of solution used by users to clean their lenses. 93% of respondents
used multipurpose solution, followed by normal saline by 7%.
Figure 1.6 showed the steps that are not performed by users when cleaning their lenses.
Most respondents did not rub their lenses using fingertips by 34%. 23% did not clean their
lens cases. 14% did not wash their hands. 9% did not store their lenses in the lens case and
did not replace the old solution in the case.
Figure 1.7 showed the frequency of users cleaning their lenses. 62% cleaned their lenses
once per day, followed by 21% for twice per week. The other 17% never cleaned their lens.
Figure 1.8 showed numbers of people experiencing infections. From 30 respondents 9
people had experienced infections and the other 21 people answered no.
6. Discussion
Period of using contact lenses
From Figure 1.1, there are 9 people with period of using contact lenses for less than
a year. We suggested this group uses contact lenses for cosmetic purposes and first-time
user.
For respondent with 1-2 years and 2-3 years period of contact lenses usage, these
groupschooses to continue using contact lenses as it helps overcome their eye defects.
Respondent with more than 3 years of experience are less likely to experience infections,
probably because they had ample experience in handling contact lenses.
From our surveys, we concluded that if a contact lenses experiences infection in the first
year of usage, they will probably stop from using contact lenses and this is most likely due to
inadequate information in using and maintaining contact lenses.
Purpose of using contact lenses
Figure 1.2 shows that half of the respondent in our surveys uses contact lenses for
both corrective and cosmetic purposes. The least preferred reason was to use contact
lenses for cosmetic purposes. We believe that the reasons are people actually prefer to uses
contact lenses to avoid using spectacles as it will hinder their active lifestyle as university
student. Using contact lenses also boost their self confidence. Only two respondents stated
that they use contact lenses for cosmetic purposes.
According to the USA Food and Drug Administration, using cosmetic lenses tend to cause
mild and serious complications. This is a possible explanation for the low number of contact
lenses users with eye infection.
Type of lenses
Figure 1.3 clearly indicates the most preferred type of contact lenses was the
monthly type. According to research by U.S Optometry and Optromologist, it was found that
96% of their respondent considers daily disposable contact lenses as the most hygienic,
followed by two-week type and monthly type contact lenses.
From our analysis, we believe that UTP student do want the hygienic quality for their contact
lenses. However, due to budget constraint, most of them are unable to opt for the most
hygienic which is the most expensive in long term. The cheapest option, the yearly type
contact lenses are the most not hygienic.
Frequency of Changing Lens Case
Based on Figure 1.4, 16 of our respondents changed their lens cases monthly. We
found out that manufacturers of contact lens solution provide free lens cases with their
product. Most of the solutions can only be used for only one month and students preferred to
buy a new solution monthly. Therefore, the majority of our respondents change their lens
case once they bought a new solution. We believed that the possibility of getting an infection
is lowered if they change their lens case in a short period of time rather than keep using the
same one for a long period of time. It is more hygienic to change the lens case frequently.
Three persons changed daily and one person changed weekly. When we totaled all the
three categories we have 20 respondents who change their lens cases after using them
within a month or less. Based on Figure 1.8, we found out that they were not the one who
had any experience with infections. We generalized that the contact lens users should
change their lens as frequently as possible to avoid getting any infections.
Type of Solution
As shown in Figure 1.5, 93% of our respondents used multipurpose solution to clean
rinse and keep their contact lenses compared to only 7% used normal saline. Wefound out
that most of our respondents use multipurpose solution as the solution has disinfecting
properties and it is not hassle to use. The abundant of multipurpose solution in the market
could also be one of the reasons why most of our respondents use it. We discovered that not
many people use normal saline as they the solution is not able to remove any proteins due
to lack of certain enzymes in the solution. As the result is not significant enough we could not
generalize anything from this extract but we could see that the multipurpose solution has
more functions and purposes compared to the normal saline. Whether the type of solution
affects the users,(infections) the relation is unknown. We would like to go deeper in these
criteria but due to lack of information we stop searching for the relation.
Steps That Are Not Performed
In Figure 1.6, 34% of the respondents did not rub their lens during cleaning. Two of
our researchers are contact lens user stated the act was not usually carried out because
they worried their lenses might get damaged. Some of the multipurpose solutions can be
used without performing the act of rubbing the lens. This could be the reason why majority of
the students did not rub their lenses. We found out that these respondents had not
experienced any infections. From this, we generalized that the act of rubbing the lens is not
a crucial part in cleaning the lens.
The figure shows 23% did not clean their lens cases. As we found out that most of the
students change their lens case within a month. It is because when they bought the new
solutions the manufacturer gave the free lens cases as for the user convenient to change the
lens cases. From the survey we found users that did not perform these steps are not the one
had experienced infections. Furthermore these steps are not that crucial to be performed
because it would not affect the users much. Whereas, for “wash hand” step, it is the most
crucial step in handling the lenses because it need to be clean in clean environment.
Besides that, users are not aware to wash their hands after handling some of chemical
products such as, cosmetics, perfume and hair gel. They did not know that the chemicals in
the products will infect the lenses and cause them to have serious eye infections. Based on
our survey we found that most of the users that did not wash their hands are tend to get eye
infections. The other important step in handling the lens is rinsing the lenses. Not rinsing the
lenses here means that they did not rinse the lenses on their palm before put it in the lens
cases. We consider most of the users found that this step is inconvenience for them and
time consuming. However, this step is consider the important step in handling in contact
lenses and may contribute to the infections if users ignore it. (Cornea & Contact Lens
Society of New Zealand Inc. 2009) stated that every time contact lenses are removed they
must be cleaned, rinsed and disinfected to make sure they are clean from any foreign
microorganisms that contribute to eye illness.
8. References
Cornea & Contact Lens Society of New Zealand Inc. (n.d.). Retrieved 3 July 2011 from
http://www.contactlens.org.nz/
Contact Lens Headlines,Studies find poor compliance with recommended contact lens care
http://www.contactlensheadlines.com/
Contact lens. Retrieved 3 July 2011, from http://en.wikipedia.org/wiki/Contact_lens
Dart, J.K.G. (1988).Predisposing factors in microbial keratitis:the significance of contact
lens wear, British Journal of Ophthalmology, 72, 926-930.
DevonshireP., Munro F.A., Abernethy C., &Clark B.J. (1993).Microbial contamination of
contact lens cases in the west of Scotland. British Journal of Ophthalmology, 77, 41-
45.
NiszlI.A.,&Markus M. B. (1998). Anti-Acanthamoeba activity of contact lenssolutions.
British Journal of Ophthalmology, 82,1033–1038.
GrayB.T.,Cursons R.T.M., Sherwan J.F., &Rose P.R. (1995). Acanthamoeba, bacterial,
and fungalcontamination of contact lens storage cases.British Journal of
Ophthalmology,79, 601-605.
9. Appendix A
Programme : __________________________ Gender: M / F
Year of Study : __________________________
We are first year chemical undergraduate students conducting a study for our academic
writing project. The purpose of this survey is to investigate the use and the maintenances of
contact lenses among UTP students. We would like to thank you for spending time
answering this questionnaire.
1. How long have you been using contact lenses?
a. Less than 1 year b. 1-2 years c. 2-3 years d. > 3 years
2. What is your purpose of using contact lenses?
a. Corrective b. Cosmetic c. Corrective & Cosmetic.
3. What type of lenses do you usually use?
a. Daily disposable b. Weekly c. Monthly d. Yearly.
4. How often do you wear your lenses?
a. Everyday b. Once a week c. Once a month d.
occasionally
Others:_______________
5. How often do you change your lens case?
a. Everyday b. Once a week c. Once a month d. Yearly
Others: _______________
6. What type of solution do you use for your lens case?
a. Multipurpose b. Normal saline c. Tap water d. Tap water
Others: _______________
7. Do you perform any of the following when you clean your lenses? If yes please circle
the statement(s) below.
a. Wash Hands
b. Replace the old solution in the lens case.
c. Clean the lens case.
d. Rinse the lenses.
e. Rub the lenses using your fingertips.
f. Store the lenses in their case and close it properly.
g. Other steps:___________________________
8. How many times doyou clean your lenses?
a. Once per day b. Twice per week c. Once a month d. Never.
Other: ________________
9. Do you feel comfortable using contact lenses?
a. Yes b. No. If no why? : ______________________
10. Have you ever had any infections while using your contact lenses?
a. Yes b. No. If yes please state the
infections:____________________
Thank you for your co-operation.