Indexes have made the searching of many records easier. Search, find, click and there's the image on our screen. It still though is wise to view all the names on the census page and a page or two before and after. There could be close relatives living nearby, hiding under a name that's indexed incorrectly or mispelled.
Read the whole page your ancestor's census or other record entry appears on. Read a page or two before and after. You might be surprised at what you find.