is caused because of a lack of muscle
co-ordination between the eyes, causing
the eyes to point in different directions.
The eyes are unable to focus simultaneously
on a single point.
common types are:
outward turning of the eyes
- Esotropia- the eyes are "crossed"
may result from problems with the extra
ocular muscles, blindness, mechanical problems
in the eye, or mechanical obstruction to
vision in one eye during early life. In
adults, strabismus may be a symptom of various
brain disorders or systemic diseases. Squint
surgery aims at re-aligning the eye muscles.
we look straight ahead at a far object our
eyes are parallel to each-other, and when
we look at a near object then the line or
axis of eye point towards the object of
regard. In squint this relationship of two
eyes is disturbed. Also known as “strabismus”,
squint is a condition where the eyes are
not aligned in the same direction. The squinting
eye may turn in (converge), turn out (diverge)
or sometimes turn up or down. These can
be present all or only part of the time,
in one or alternating between two eyes.
can arise because of an incorrect balance
of the muscles that move the eyes ,faulty
nerve signals to muscles, refractive errors,
childhood illnesses, etc.
squint only a cosmetic problem?
is not just a cosmetic problem. It is always
associated with certain degree of functional
defect which make it important to treat
squint as early as possible. It can be associated
with decreased vision (amblyopia or lazy
eye) or double vision (diplopia). Loss of
binocular vision (ability to use two eyes
together) can lead to loss of fine depth
perception (stereopsis) and peripheral visual
Amblyopia or lazy eye means
decrease in vision occurring in the eye
due to abnormal or lack of coordination
between two eyes. This decrease is over
and obove what is caused by refractive error
or any other physical problem in the eye.
It can be treated before the age of about
9 years by occlusion therapy.
is squint assessed?
It is assessed by various
orthoptics tests, the aim of which is to:
the amount and type of squint
how well can the child /adult see
Detect presence of refractive errors (refraction)
Test for binocular vision
Retina examination including fixation
Investigate for the cause of squint
can present at any age. The cause is not
always known, but if squint is suspected,
then the baby should be seen for accurate
assessment at the earliest opportunity.
Sometimes a “pseudo or false squint”
may be present due to wide gap between the
eyes , flat nose bridge etc. where the eyes
appear to be misaligned but do not actually
have squint. Newborn child may have a certain
degree of misalignment of the eyes which
usually disappears by about 6 months of
age but if it persists beyond 6 months then
the child should be immediately examined
by an eye surgeon.
are the causes of childhood squint?
cause of squint in children is varied:
squint: these children are born with
a squint, though it may not be obvious
for few weeks. A strong family history
could be present. In all children the
vision and need for spectacles has to
Long sightedness or hypermetropia: as
the child cannot focus well for near,
he has to put extra effort to focus.
The over focusing produces double vision.
To avoid this double vision, the image
in one eye is suppressed unconsciously
and in turn the child avoids using that
eye. If left untreated not only does
the eye deviates but also becomes a
lazy eye (amblyopia)
Childhood illnesses: Squint may also
develop following viral fever, measles,
Injury: to the nerves supplying eye
muscles can lead to squint.
What is the treatment for childhood squint?
Spectacles or Surgery?
child is thoroughly assessed to establish
the type of squint. It is very important
to note the vision and fixation pattern
in both eyes. Treatment varies according
to the type of squint and can be in the
form of spectacles, occlusion, eye-drops
(rarely) or surgery.
squints, especially those that arise from
hypermetropia (long sightedness) respond
well to treatment with wearing of spectacles.
The child will be seen from time to time
to note the change in spectacle power and
degree of squint till he grows up. Any residual
squint not corrected by spectacle can than
be corrected by surgery. Convergent Squint
in a 5 years old girl Almost completely
corrected by glasses (Bifocal - parents
were shocked at the idea of bifocal but
correction of squint relieved them).
/ Lazy eye: This is treated
by patching / Occluding the good eye.
The weaker eye is encouraged to work
harder with visual activities such as
coloring and reading while patch is
on. It should be noted that amblyopia
can be treated only before the age of
about 9 years after which the visual
system of the eye becomes fixed and
fails to respond to occlusion therapy.
this is the only choice to straighten
the eye. If done at appropriate time
results can be very good and 3 D vision
can develop. One or both the eyes may
have to be operated and one or more
operations sometimes may be required
to achieve perfect functional results
(cosmetic correction is usually easier
When an adult presents with
squint it is not only imperative to establish
the type and amount of squint but also to
establish and treat the cause of squint.
There are two main types: non-paralytic
or paralytic squint. The non-paralytic variety
either persisted from childhood or is a
local eye muscle imbalance. Any adult presenting
with sudden onset of paralytic squint has
to be investigated in detail for the cause,
which could be medical, e.g. hypertension,
diabetes mellitus or surgical e.g. brain
lesion. Majority of these kinds corrects
on their own within 6 months and surgery
is only required in cases where squint persists.
happens in squint surgery?
are six muscles attached to the outside
of each eyeball, which move the eye in various
directions. During surgery one or more (commonly
two) muscles are weakened or strengthened
(by moving their attachment backward or
forward) to make the eye straight. The procedure
is done under local anesthesia in adults
and general anesthesia in children.
more than one surgery be required?
is not uncommon for more than one operation
to be necessary. This does not mean that
something has gone wrong but that fine-tuning
is needed to obtain the best straight alignment.
Sometimes the squint is too large and hence
a two-stage surgery is planned. The world
over average is 2.3 operations to achieve
ideal correction of squint.
happens after the operation?
is a day care surgery with no hospitalization
(unless general anesthesia is used). The
eye pad is removed the next day and eye
drops are instilled for a couple of weeks.
Since it is an external surgery there is
no effect on the vision. Most of the times
external stitches are absorbable and do
not have to be removed. The person can join
back his office in a couple of days although
a certain amount of redness and irritation
continues for a few days.