Thanks for writing to us.
If you have not done an eye check up yet, do consult as any strabismus/squint
needs a direct prompt examination to know the cause of it and treatment varies accordingly.
Since it is of a recent onset (3yrs) and associated with headache and blurred vision
-if it's due to refractive error
, glasses or contact lens
might help you.
-if it's not, then it needs a detailed neurological assessment too.
- cosmetic surgical intervention of the muscles can be done .
Before going for consultation take some old photographs as the eye doctor can compare then and now status of the squint.
So do let us know after your consultation