Are there any computer programs that can take a text (newspaper etc...) and read it aloud to someone with a vision impairment?
The best-known software to scan and read text is Kurzweil 3000. It is designed to be used in conjunction with a scanner. Kurzweil converts scanned text using Optical Character Recognition (OCR) and can either display it in a format more suitable to low vision users, or you can use the screen-reading function to have the text read aloud.
Unfortunately, the software is very expensive. Your local library may have the software available so you can try it out before buying it, or a local community centre may have the software available at reduced cost.
There are other screen readers available, but they require you to scan the documents separately, more information at Wikipedia's screen readers page. Kurzweil is the most complete software solution.
Another option which may be in your area is Radio for the Print Handicapped or Radio Reading Services which may read aloud newspapers, magazines, and other printed materials. (Radio Reading Services Directory