Our OT only sees us to assess for equipment to be used in the home and at playgroup to make DD's life easier. She has a physical disability and most of her 'treatment' is from physio. The OT organises things like specialist seating, wheelchair services, toileting aids, etc.
An OT will look at a person who is having difficulty with their daily occupations be it dressing, sleeping, walking, eating, washing, writing, etc.
They will then assess and work on the skills that you need for that activity/occupation So for example, for handwriting you need vision, postural muscles, fine motor skills, proprioception, cognitive skills, midline orientation and ability to cross the midline, praxis, concentration, processing skills, working memory etc etc. The OT will assess to see what are the demands of the activity, where are the deficits. They will try to mediate the gap in performance (between what exists and what is required) by improving the skill or by modifying the environment.