| For
your eyes only |
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| In
a myopic eye, light rays are focused
in front of the retina, and the
brain interprets what is seen
as a blurred image. |
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Myopia is commonly
known as short-sightedness. Singapore has one of
the highest rates of myopia in the world and our
children are becoming myopic at a younger age. This
is a cause for concern as the earlier a child develops
myopia, the higher the tendency of developing severe
myopia later in life.
How do we see? When light rays from an object enter
our eye, they are first “bent” at our
cornea before entering our eyeball.
The light rays are bent again at the lens inside
our eyeball. They then reach our retina, or the
light-sensitive layer of cells at the back of our
eyeball. Upon reaching our retina, the light rays
generate nerve signals in the cells of the retina.
The nerve signals are then sent to our brain for
processing so that we “see” the object.
In a normal eye, when the rays are focused correctly
onto the retina, our brain interprets that we see
a focused image of the object. In a myopic eye,
the light rays are focused in front of the retina,
and the brain interprets that we see a blurred image.
Corrective lenses, such as spectacles or contact
lens, are necessary to help our eyes to focus the
light rays correctly.
These include the following:
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Retinal detachment
— This happens when the retina becomes
separated from the eyeball. This is a medical
emergency as it can lead to blindness and
should be treated as early as possible. |
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Glaucoma —
This condition is associated with increased
pressure within the eyeball. If untreated,
it can lead to blindness. |
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Macular degeneration —
This occurs when the most sensitive part of
the retina — the macula — degenerates.
Central vision will
be affected. |
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Amblyopia or “lazy
eye” — This condition can happen
in young children when there is a big difference
in the degree of myopia between the two eyes.
The brain interprets the image from the “stronger”
eye and not the image from the “weaker”
eye to prevent blurred vision. As a result,
the “weaker” eye does not develop
vision properly and may never see well. |
It is not well known what causes myopia but a child
is more likely to develop myopia if one or both
parents suffer from myopia. Studies have shown that
“near work” such as reading, writing
and working on the computer for long periods of
time without a break is a very important contributing
environmental factor.
Currently there is no approved medication to treat
myopia. Surgery is available to treat stable myopia
in adults, but surgical methods are not advisable
for children as their eyeballs are still growing
and their myopia has not yet become stable. Hence
it is important to prevent myopia or
its progression.
As “near work” appears to be an important
factor in the development of myopia, it is important
to limit the duration of continuous “near
work” activities. Practise good eye care habits
like these:
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Take a 3-
to 5-minute vision break by looking at distant
objects after every 30 to 40 minutes of continuous
“near-vision” work. |
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Sit at least
2 metres from the monitor screen when watching
television programmes or playing video games. |
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Hold your books or magazines
about 30 cm from your eyes when reading and
ensure adequate lighting in the environment. |
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Place the monitor screen
about 50 cm from your eyes. |
And adopt a healthy lifestyle and eat a balanced
diet. They are important for your eyes too! |
