Views caching dont show changes
You should ideally be using the Field Attach API to avoid these problems.

Or for a quick solution have a look at field_attach_update where at the end of the function, it clears the field cache:

$entity_info = entity_get_info($entity_type);
if ($entity_info['field cache']) {
  cache_clear_all("field:$entity_type:$id", 'cache_field');
}