Suggest Treatment For Headache

Good morning doctor. This is Maxim from dombivli(e). From last 2 weeks my dad is having half headache which is now turned to eye pain (right side). we took treatment from our regular physician for headache and also checked from a eye specialist. The eye specialist told it is due to diabetes and will take time to heal. The affected eye has become little small and eye sight has reduced slightly. Doctor claimed that retenia is all right. I would like to know from you some more info on this. What am i supposed to do?