public function rules()
{
// NOTE: you should only define rules for those attributes that
// will receive user inputs.
return array(array('left_description, right_description, eye_id', 'safe'), array('left_description', 'requiredIfSide', 'side' => 'left'), array('right_description', 'requiredIfSide', 'side' => 'right'), array('id, event_id, left_description, right_description, eye_id', 'safe', 'on' => 'search'));
}