SQUINT / STRABISMUS

This is the condition when eyes are not straight or aligned properly. The eyes may go in or out and occasionally up or down.

Eye movement

Eye movement is controlled by 6 muscles attached to the outside of each eyeball.

In order to see correctly both eyes must move in same direction. This is done by pulling by one muscle in one direction and relaxing of other muscle. To see one object both eyes must look at it at the same time. Each eye sees it from different angle and each eye sends a slightly different picture to the brain (Binocular vision). Brain blends the two picture to give a three dimensional image. This process is known as fusion and it gives the ability to judge the relative distance in two objects (depth perception).

If the muscles are not coordinated the images of to eyes send two brain will not fuse and one gets double vision. The child quickly and unconsciously learns to ignore the image of one eye (suppression) and the eye becomes lazy (amblyopic)

The development of binocular vision starts at age of 6 months to be completed by age of 5 – 8 years. So the squint treatment should be done in this age.

False Squint

This is the condition where eye looks deviated because of structural factors as broad nose. But the examination by an eye doctor will diagnose this case. It normally gets corrected with age and needs no treatment. 

Latent Squint

In this condition eye remains straight in normal gaze but gets squinted on strain and tiredness. Squint is seen on covering one eye - the covered eye becomes squinted. Actually the imbalance in this case is not so much to cause obvious squint . Eye muscles tries to maintain binocular vision. This causes strain and headache. Mostly it is due to refractive error and correction may give relief from headache 

Causes for squint:

  Birth injuries.
  Hereditary.
  Faulty muscle balance.
  Need for glasses.
  Certain eye diseases interfering vision of one eye.

Goals of treatment:

  Development of normal vision in both eyes.
  Straighten the eyes.
  To make both eyes work together.

Treatment:

Early check up by an eye doctor is must to diagnose and treat the case. It is time taking and needs lot of effort from parents to attain the goals.

To Develop vision:

	Glasses/ Spectacles: some type of squint are corrected by glasses only.
	Patching of the lazy eye: By this we stimulate bad eye to see more and improve vision. This is done under doctors supervision, who checks for development of vision in bad eye and deterioration of vision in good eye which may happen occasionally. In these cases he may have to reverse the patching.

Straighten the eyes

	Surgery is done to straighten the eye. In this the weaker muscle is made stronger by cutting a piece and joining two ends (resection) and stronger muscle is made weak by cutting it from its attachment and taking the attachment back (recession) . Surgery may have to be done in one eye or both eyes depending on amount and type of squint.
Resection		Recession

To develop Binocular vision

Chances of developing binocular vision is normally very less. However some exercises after and before surgery may be recommended to develop binocular vision. This is done by person trained for it known as orthoptist.