It is permissible in modern English to use seeing as a conjunction meaning ‘since’ or ‘in view of the fact that’: Seeing we're late anyway, another five minutes probably won't make any difference. The correct way to use it, however, is on its own or followed by that. The form seeing as how is considered non-standard by most modern authorities. Care should also be taken to ensure that the conjunction seeing cannot be confused with the present participle of to see. Seeing that he was in trouble, she decided to help him is ambiguous to the extent that it is not entirely clear whether or not she was an eyewitness to the fact that he was in trouble