Childhood Squint

Normally the two eyes move parallel to each other in all the directions of gaze. Squint is a misalignment of the two eyes so that both eyes are not looking in the same direction. In other words the two eyes don’t look straight in the primary gaze. It is a common condition among children. The most important question is when to get a child’s eyes examined and what are the symptoms to be noted to look for any eye problem?

Normal development on vision in a child -
At birth babies see in black and white and shades of gray. Because newborns can only focus eight to twelve inches, most of their vision is blurred. By 8-12 weeks of age, babies start to follow people or moving objects with their eyes. At first, infants have to move their whole head to move their eyes, but by 2-4 months they start moving their eyes independently with much less head movement. The colour vision is usually developed by 4-6 months of age.

At birth the child is far sighted or hypermetropic. Slowly the vision develops and usually comes to normal 20/20 by 12-14 months of age.

What are the signs to be noted in a child?
Child crossing his eyes.
One eye going out.
Occasional crossing or going out of the eye, when child is tired or during illness.

If the above symptoms are present before 6 months of age, then there is no need to worry, a child des not develop coordination between the two eyes, before 6 months of age. But if the symptoms donot improve after six months of age, then the child needs a thorough eye examination.

What can be causes of squint in a child?
Congenital squint - Child is born with a squint, or it develops within six months of age. In most cases, the cause is not known. The squinting eye can be inwards, outwards, up or down. The cause of congenital squint is not known, but rarely it can be hereditary.
Squint due to refractive error – The refractive error can be shortsightedness (hypermetropia) or long sightedness (myopia). This type of squint tends to develop in children who are two years or older. This is specially seen earlier than two years if there is a marked difference in the refractive power of both the eyes.
Other causes - In some cases, a squint is one feature of a more generalised genetic or brain condition. For example cerebral palsy, Noonan syndrome, hydrocephalus, brain injury, and various other conditions.

Treatment for squint -
A squint examination first aims at determining whether the cause is refractive error or not. If the squint is due to a refractive error, then the corrective spectacles are given and the child is followed up after every 3 months. If the cause is muscle imbalance, then the treatment is surgery.

What happens if the squint is not corrected?
In such a case, child develops Amblyopia. Amblyopia is sometimes called a 'lazy eye'. It is a condition where the vision in an eye is poor, the other eye is the ‘seeing’ eye. As a result the vision in the lazy eye gets suppressed. If not corrected within 6 years of life, then the amblyopia can become permanent and one eye will have less vision throughout life. Ablyopia is treated by giving corrective glasses and patching the better eye, so as to stimulate the lazy eye.