Double vision (diplopia) due to a neurological cause (i.e.due to nerves) may take anywhere from 2 weeks to 6 months to improve and it is very variable  in each patient. No one can give you the exact time when it will improve in any case. Having said that, if gradual improvement has been perceived, it is a positive sign and we can expect further improvement in due course of time Keep following up with your local doctor as advised. If any systemic conditions are there like diabetes and hypertension, they need to be controlled and kept well under check. Wishing you good health.