Two Days Ago My Dad Had A Spell,,dizzy,,and I Noticed

Two days ago my dad had a spell,,dizzy,,and I noticed something in his left eye...yesterday he said he saw little balck bugs flying around a picture,,and today,he is not awake to talk to,,but has tremors in his hands/arms, and legs....his dr thinks he had a seizure,,he has parkonson's disease/mild,,hands shake when he drinks or eats. he is 78 years old w/diabeties, and CHF...I don't think it was a seizure,,however he is not awake to talk to,,when he opens his eyes today/little they were rolled back in his head,,,sometimes. then when he tried to talk,,he just mumbled...what the heck is wrong?