What is Concomitant and Incomitant deviations in squint ?

Concomitant Deviation

1. The Angle of deviation are the same in all fields of gaze.
2. Congenital or chronic.
3. Congenital or early onset strabismus or Chronic.
4. Suppression associated with amblyopia.
5. Develop diplopia later is life.

Incomitant Deviation

1. Angle of deviation is different fields of gaze.
2. Incomitant deviation mainly seen in patients with acquired problems-looking to right no problem.
3. Straight also less problematic but looking to right produce diplopia.indicating deviation vary with gaze.
4. Acquired and causes diplopia.
5. Long standing incomitant deviation become comitant.

Related articles

1. What are the History you should ask in Diplopia?
2. What is Concomitant and Incomitant deviations in squint ?
3. What are the causes of Horizontal and Vertical Diplopia
4. Differential Diagnosis of Monocular Diplopia
5. What are Beilchowski’s three step test ?
6. How to find out which eye is producing the peripheral image in Diplopia?
7. How to know which muscle is affected in Diplopia?
8. What are the clinical approach that need to take care on diplopia History taking?
9. What causes the Pathophysiology of misalignment?
10. What causes binocular diplopia?
11. What are the symptom of diplopia and how to diagnose diplopia ?
12. Clinical approach to DIPLOPIA (Binocular and Uniocular)

What is primary and secondary deviation Squint?

Primary deviation is the deviation of the "lazy" or paretic eye, when the "good eye" or the non-paretic eye fixes on an object. 

Secondary deviation is the deviation of the “ good "or non- paretic eye, when the "lazy" eye or the"paretic eye" fixes on an object.

Secondary deviation is always greater than primary deviation in noncomitant strabismus because of Hering's law of equal innervation.

When the left eye is covered right eye has to move more to fixate.same innervation go to the left eye also.