Our eyes are like to wheels of chariot. Absolute adjustment between the two wheels is necessary in order to move the chariot. Such kind of balance is the basis of our binocular vision. Both the eyes are complementary to each other. When because of any reason this balance is distorted, the eyes do not remain parallel and this is called squint. It has got many forms. Squint is not the curse of God, but is a result of some kind of visual deficiency.
Sudha is aged 12. She had beautiful nose, measured face, large eyes and fair complexion. But God probably did not accept her beauty. Since she can remember she found that her right eye was a little inclined. Her parents treated it as curse of god and did nothing. Their Sudha was incarnation of Goddess Lakshmi. They thought whichever home she would go would be blessed. But Sudha was fed up of all this. Her classmates and friends used to taunt her and she bore all this in silence. As a result she became lonely and introvert.
Ultimately, one of her teachers showed the way to her parents. On the teachers counselling they took Sudha to an ophthalmologist. On examination, the ophthalmologist found that her right eye was quite weak and this led to balance between the two eyes.
Had Sudha’s parents took her to the ophthalmologist in her childhood, the situation would not have worsened. She would have then been given glasses or contact lenses, which would have corrected her vision and eye would not have developed squint.
Now surgery was the only alternative. It was not possible to restore vision of right eye.
After surgery both eyes of Sudha look normal. Her personality has improved. She is seen smiling, laughing and talking all the time. Her self-confidence does not know any limit.
Like Sudha many people in the world are affected with squint of eyes. There are several forms of this, but basically there is no balance between the two eyes and one eye appears away from the target. This is called squint.
What is Binocular Vision?
Normally when see in any direction, our both eyes move in that direction. This maintains their parallel alignment. Both the eyes are focused on one point and though the images in them are different from each other to a certain extent, they become one.
The resultant image is three-dimensional. This is called binocular vision. This is possible only when the vision is healthy and there is complete alignment of both the eyes.
This alignment is possible because of measured balance of several links in the vision process.
On one side each part of the eye ball participate in this, which leads to image of the object in front eye. Optic nerve reaches this image to the brain.
On the other side there are six muscles of eye, which move eye upwards, downwards, left, right and in circular motion. These muscles are controlled by those nerves which are controlled by the brain. Centres of both the eyes remain in complete coordination with each other and other centres of brain. As per our wish, appropriate centre of the brain becomes active and that particular muscle becomes active which is needed to be active.
With this both the eyes move in the desired direction.
Therefore, in the vision process for healthy coordination of both the eyes, it is necessary that the way from cornea to brain, optic region of brain and muscles of eyes are healthy. If even one of these is not healthy the eye moves from its target and squint may develop.
In rare cases even if eyes are completely healthy, it may give impression that the eyes have squint. This is called pseudo squint. This disease is often seen among those children who are abnormally high distance between eye corners and nose. It gives the impression that pupil of an eye is touching inside of the nose, but when ophthalmologists examine this they find no problem with the eyes.
With age this disease is cured on its own. If this does not become right up to five years of age, this may be cured by plastic surgery.
Types of Squint
There are several kinds of squint. In some cases it is not even visible. This is called latent squint. There is little difference in vision, which eye muscles try to hide. The eyes appear good when viewed, but often child complaints tension in eyes and headache. Sometimes eyes move away by evening. If this is not treated in time, squint becomes visible prominently.
In most of the cases of latent squint eye, exercise and glasses help. Only in some cases surgical interventions are required. Latent squint has two major kinds:
Paralytic Squint: If one of the six muscles that move the eyes become weak, paralytic squint is caused.
- This may occur because of several reasons like
- Use of forceps during delivery
- Any accident which injures any nerve of eye muscles
- Nervous damage among diabetic and high blood pressure patients
- Nervous damage because of brain tumour, infection, internal pressure or obstruction in blood circulation
- Damage to any muscle or nerve during an eye surgery
This does not allow the eye to move in the direction in which generally weak muscle would have taken it.
If this ailment is since birth, the child moves his head to bring both the eyes parallel to each other. This abnormal posture of the child is the symptom of this ailment.
When the child becomes more than three years old, the patient complaints of seeing one object as two. He cannot have right idea of the objects placed close to him and he may stumble upon them. He may complain of giddiness and faces difficulty in getting down the steps. He may keep head bowed in one direction. To save himself from these problems, he may develop habit of keeping one eye closed.
By thorough examination it becomes clear which muscle of eye is weak or useless. After this, attempts are made to find out the reasons behind this. If possible efforts are made to remove the shortcoming.
In some cases, exercises of eyes help. If the muscle is partially weak, after an interval of six to eight months surgery may be conducted on the muscles of the eyes. This prevents the eye moving away from the target.
The persons who have severe problem of seeing two images, an opaque glass is used in front of the ailing eye.
Another major kind of squint is alternative squint. In this, eye muscles, their nerves and brain centres of the nerves are normal. Both the eyes are centred on two different points and this difference remains the same in all the directions, meaning that angle of inclination remains the same between the eyes and each posture of eyes.
This may have two forms – in the first one eye is normal and the other is moved inwards, and in the second, one eye is normal and the other is moved outwards.
Exact reason of alternative squint is not known. But it has been seen if vision of one eye is weak since childhood, such an eye may fail in maintaining balance with the other eye. This leads to squint. Any obstruction in the way of cornea to macula like by birth cataract, of pronounced difference in focus system between the two eyes may become cause of alternative squint.
Visual weakness of any kind among the children in five to ten years of age may also lead to this.
This happens when this problem of the child is not diagnosed and he is not given glasses to correct his vision.
If power of both glasses for both the eyes is considerably different, the weaker eye may become slanted.
Alternative squint may last forever, or in some cases it may appear on certain occasions. In the latter case it is difficult to diagnose it.
This leads to mononocular vision. The brain starts neglecting the image appearing in slanted eye and after a certain age such eye loses its vision. As a result such patient’s vision becomes restricted. This also hampers personality development of the child. As other children taunt such a child, he does not mix up with other children and becomes lonely. Or to hide his shortcoming, he becomes violent. When he grows up, this shortcoming of the eyes may become a restrictive factor in his job and marriage.
It is necessary for parents of such children if their child has got such problems in his eyes, they should not be guided by superstitions and should not ignore it. With timely treatment they can save vision of slanted eye, but they can also provide binocular vision to the child by developing healthy coordination between the two eyes.
In several cases, glasses and regular exercise may lead to healthy eyes of the child. Some parents are careless to ensure that the child wears the glasses. This is not proper. Even a two year old child may put on glasses.
In some cases, it may become necessary to put opaque glass on one eye. In several cases these devices may not cure squint. In such cases and in some other cases surgery is required in the initial phases only. Such surgery should not be postponed unnecessarily. This treatment requires too much of time and puts to full test seriousness of the parents. In some cases it also becomes necessary that this surgery is conducted in two or three phases. If care is not taken during this duration, the child may become disabled for his entire life.
There is no risk to life in such surgery. One or two days after the surgery the patient is sent to home.
The children whose squint is cured with glasses, should be brought for examination of eyes every six months. At the age of eight years, glasses may become redundant for a few children.
In the cases where no treatment is given till adulthood, it is not possible to bring about improvement in the vision of slanted eye. But even then slant of eye may be removed through surgery. This cosmetic operation may be done in any age.
Several people treat squint as a God curse. This is not true. Squint is a disease of eyes and it can only be cured with timely treatment.
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