This Newsletter aims to promote communication between students
and the Student Health Service of the Department of Health
May 2016 Issue No.70
Published by the Student Health Service, Department of
“Good eyesight is valuable. Eye care! I
The eye is an important sensory organ in our body. If we have any
eye problems, our daily activities may be affected. Among different
kinds of visual conditions, myopia is a common refractive problem in
Hong Kong. In this issue, we have invited our optometrist to provide
information on the prevention and control of myopia.
The prevention and control of myopia
Optometrist, Student Health Service, Department of health
Myopia is a common visual problem (refractive error) in Hong
Kong. Severe myopia may cause eye problems such as retinal
degeneration, retinal detachment or glaucoma, so it is important to
prevent and control the increase of myopia.
The causes of myopia
The causes of myopia can be congenital and acquired factors.
Congenital factors include genetic heritage and race (the prevalence
of myopia is higher in Chinese), while acquired factors include
improper reading habit, poor lighting, insufficient nutrition and
poor general health etc.
People with myopia cannot see distant views/objects clearly which
worsens with myopia increasing. They can see more clearly when they
move closer to the views/objects. The higher the myopia, the
severity of blurred vision increases.
With myopia, the light rays from the distant object entering the
eye are focused in front of the retina instead of on it, resulting
in blurred images. This is usually because the eyeball is too long
or sometimes the cornea and the lens do not bend the light rays
Methods to correct myopia
- Suitable for those with myopia, hyperopia and
- Suitable for young children or those cannot wear
- Suitable for those with myopia, hyperopia and
- Suitable for those with great difference of
refractive error between two eyes, or those who do not want to
wear heavy glasses or regular sports players.
- Advise to have comprehensive assessment before
wearing contact lens and should be regularly followed up by eye
care professionals. Contact lens is suitable for older children
who have self-care ability for contact lens. Therefore, it is not
suitable for young children.
Lasik (refractive surgery)
- Suitable for adult with no other eye diseases.
- A prior assessment should be done by an
ophthalmologist before the operation.
Orthokeratology / Ortho-K (overnight)
- This is a recent hot topic. The rationale is to
change the shape of cornea by using oxygen permeable rigid contact
lens. For individual suitability and potential risks, please
consult relevant eye care professionals.
- Please consult relevant eye care professionals
such as optometrists or ophthalmologists on your choice of
Tips for the prevention and control of myopia
(1) Good reading habit
- Keep a distance of at least 30cm between the eyes
and the books.
- Do not read while lying in bed as you may move the
book closer and closer to the eyes without noticing it.
- Do not read without adequate lighting.
- Rest for 20-30 seconds after every 20-30 minutes
of screen use.
- Change position, blink eyes and do muscle
- Keep reading distance no less than 50cm for a
computer, 40 cm for a tablet personal computer or 30 cm for a
- 6-12 years old: limit recreational screen time to
no more than two hours a day. 12-18 years old: avoid prolonged
(2) Keep your eyes and body healthy
- Engage more outdoor activities as they can relieve
- Have a balanced diet: eat more cereal/grains,
vegetables and fruits as well as moderate amount meat, fish, egg
and alternatives, but eat less fat/oil.
- Eat food rich in vitamin A (e.g. tomatoes and
carrots) since it is good for your eyesight.
- Have adequate sleep to rest your eyes.
(3) Optimal lighting
- Use ceiling lights when reading. Lighting should
be even and bright without excessive glare.
- For right-handed children, light from a desk lamp
should be shone from the left upper corner when they are writing,
and from the right upper corner for left-handers. Do not shine
light directly into the eyes.
- Watch television with room light on.
(4) Choose appropriate printed material
- Poor quality printed materials will cause eye
strain. Words should be clearly printed: both the font size and
the spacing should be appropriate.
- Glossy paper will produce glare and cause eye
strain after prolonged reading.
- Dark-colored paper reduces clarity and makes
(5) Have regular eye check-up and wear glasses
- Have vision test once a year. Wear glasses if
myopia affect your academic performance or daily activities.
- Wearing glasses make your vision clearer but it
cannot help to cure or prevent myopia from worsening. On the
contrary, not wearing properly prescribed glasses will further
affect your ability to see and your academic performance will
We cannot change the congenital factors but we can prevent myopia
or its worsening as far as environmental factors are concerned.
Parents and children can protect the “window of the soul” together.
Parents are advised to take their children to have the first vision
test at the age of 3-4 years old. Primary to secondary students
should regularly check eyes once a year.
The advantages of regular vision check-up:
||Early detection of any vision problems.|
||I could know whether my shortsightedness is
worsen or not.|
||I could have suitable glasses if they are no
||To know more about my eye condition.|
||It helps us to adopt healthy lifestyle once
we know that our eyesight are getting worse.|
||It can increase our awareness in eye care and
This publication is produced by Student Health Service of
the Department of Health.
Tel: 2349 4212 / 3163 4600 Fax: 2348 3968
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