What is strabismus?
Strabismus is an eyesight disorder related to a defect in the parallelism of the visual axes due to a muscular imbalance. This disrupts the sensory and motor correspondence between the two eyes.
Depending on the direction of distortion in the visual axes, the strabismus is either convergent,divergent or vertical.
Strabismus in children is mostly convergent strabismus – children who squint – which appears between birth and the age of five or six. Divergent strabismus often appears later, between six and 10 years old.
A permanent strabismus results in diplopia: the child sees double. To rectify this sensory problem, the brain ignores the image supplied by one of the two eyes. This results in the loss of binocular vision and 3D relief perception.
If not corrected, diplopia can cause amblyopia or “lazy eye”.
Correcting and treating strabismus
Approaches vary depending on the type of strabismus.
- Corrective lenses: the strabismus is sometimes due to a default of accommodation. In this case full optical correction of the astigmatism, hyperopia and/or myopia is recommended.
- Prevention and re-education of the amblyopia: the healthy eye is intermittently covered with a patch to stimulate the amblyopic eye and make it work.
- Surgery is used to put the eyes back on the same axis by pulling back or shortening some of the muscles attached to the eyeball. This corrects the alignment of the eyes.