What is Squint ?

Strabismus (crooked eye or squint) is a generic term applied to all those condition in which the visual axes assumed a position relative to each other different from that conforming to physiological conditions. In simple terms, squint or strabismus is the condition where the visual axes of the two eyes do not meet at the point or object of regard.
   

Squints can either be comitant or incomitant. In case with comitant squint, as opposed to incomitant squint, although the eye are misaligned, they retain their abnormal relation to each other in all directions of gaze. In comitant squint the efferent pathways are normal and can still maintain coordination of the eyes, but either the afferent path is defective ( usually due to poor visual acuity owing to a defect in the fixation and reflexes is undeveloped or has broken down. The breakdown may be due to peripheral causes, such as the excessive effort of convergence required with the sustained accommodation necessary in hypermetropes or a slight weakness in an extra ocular muscle such as is not sufficient to cause a paralytic squint. Incomitant squints may be paralytic or restrictive. 

In paralytic squint the afferent pathways and centers are intact, but the efferent mechanism breaks down. In restrictive squints there is a mechanical factor such as a tight or fibrosed muscle or a local space-occupying with simultaneous co-contraction or antagonist muscles which leads to limitation of movement and squint.