Strabismus or squint is a misalignment of the the eyes. The commonest type in our community is what you child has: intermittent exotropia (XT).
In general this is a more benign type of squint compared to its opposite which is esotropia.
In intermittent XT usually the eyes take turns deviating outwards, with the one that turns out more often risking becoming more "lazy". But on the contrary, patching is done on the eye that is LESS deviated i.e. the more "normal" eye so as to allow the "problem" eye to "work harder" and become less "lazy"
The patching does not usually change the angle of the squint much. It simply prevents the more deviated eye from slipping into irreversible "laziness". The scientific word for this laziness is amblyopia. It is very important that the patching is done properly before the child turns 8 year old, as that is when visual maturity is reached. If not done properly before this, there is a high risk that the lazy eye cannot be reversed anymore even with future patching.
In general when there is squint the depth perception/ 3D vision of the person will be affected. That may affect some fine vision function, like performing microsurgery for instance.
If the child and family are conscious of the squint, eye muscle surgery to straighten the eye can be considered.
Hope that answers your question, and best wishes!
Dr Han
