Bay seniors who despair of the bright lighting of local restaurants ought to consider giving San Francisco’s Opaque a try. They have no lights at all. Your entire meal is served in the dark which gives a diner pause – how does the waiter see you to know that you’re getting the entry you ordered? How messy a meal is it when you are trying to locate your mouth with your fork? The prix fixe menu is fairly standard and limited – tuna tartare, beef tenderloin, pasta – for $99 plus tax. An experience like this could give a whole new meaning to “blind date”.