One reason could be for a game. For example, a scavenger hunt - like game where she has to use her other senses to find things. Another reason might be for a performance, like a play or a magic show as I mentioned before. Or it could be part of a surprise party where her friends and family want to build up the suspense before revealing the celebration.
Well, it could be a prank. Her friends or family might be pulling a harmless prank on her. They tie her up, blind and mask her just to see her reaction when they finally release her. Or perhaps in a mystery - themed story, she is the victim of a supposed crime (but it's all part of a plot that will be revealed later) and this state is to create mystery and tension in the plot.
One reason could be a prank. For example, her friends might be playing a harmless joke on her. Another reason could be part of a performance, like in a theater play or a movie scene. It could also be in the context of a mystery or adventure game where she is 'trapped' as part of the plot.
That's a rather concerning and potentially dangerous situation in real life, but for the sake of a fictional story. There was once a wife who was tied up, blindfolded and masked as part of a mystery game her family had organized for her birthday. They wanted to give her a unique and exciting experience. They led her around the house, making her guess where she was based on sounds and smells. In the end, when she was untied and the blindfold and mask removed, she was greeted with a big party and lots of presents.
One reason might be a creative form of foreplay. In a consensual and loving relationship, couples may explore different ways to add excitement. Another could be as a form of punishment in a very light - hearted and joking way. For example, if he forgot an important date.
One reason could be that the reader has stumbled upon a secret. For example, if the story is set in a world of spies, the reader might have accidentally overheard some top - secret information and the villains want to keep him quiet.
Perhaps it's a themed party. The 'wife tied up' is part of a pirate - themed party where she's captured by the 'bad pirates' and the guests have to rescue her through various challenges and games. It could be a really fun and interactive way to engage everyone at the party.
It could be part of a prank by her friends. Maybe they wanted to play a joke on her or you. Another possibility is that she was involved in some sort of self - defense training and was practicing being in a restrained situation.
One reason could be to create a sense of vulnerability. When a woman is tied up in a movie, it makes her seem more helpless and in need of rescue, which can drive the plot forward. For example, in action movies, the villain might tie up the female lead to lure the hero into a trap.
This is a very concerning situation. One possible reason could be some kind of mental breakdown or extreme family conflict. Maybe the sons have some serious issues that they are not able to handle in a proper way and they resorted to this inappropriate and illegal behavior out of desperation or lack of proper communication skills.
Perhaps she was exposed to some harmful substances or toxins. There are certain chemicals that can cause damage to the eyes and lead to blindness. In the 'woman becomes blind story', it could be that she worked in an environment where she unknowingly came into contact with such substances over a long period of time.
One possible reason could be a misunderstanding. Maybe she thought he was in danger of doing something rash and tied him up to stop him. For example, if he was about to make a bad business deal without thinking clearly.