Thanks for using health care magic.
Headache with blurred vision
may be a side effect of the drug. but one should also rule out ophthalmic reason as both can be present in refractive errors also.
About duration of the drug intake, You should consult Psychiatrist
It is not common to have severe side effects but you should consult your psychiatrist who will obviously monitor the side effects of drug if any and take appropriate actions.
I hope your wife will be fine soon.