Explaining to someone what 'seeing' is, that's been blind from birth, is like trying to explain what up and down is to a 2D creature. The two things are simply incomprehendable. Think about this. Someone living in a 2D world (flat world) will know movement on an X and Y axis only. (forwards and backwards, and left and right). Trying to explain them what up is, is just impossible since in their world there's only an X and a Y axis. No matter how hard you try, you can't compare it to something that's familiar to them since everything that's familiar to them, is in 2D. Same with blind people. They don't know what 'seeing' is. You can touch their eyes, and tell them that they're supposed to 'see' the world, and that it has 'colors' but all these things would be like the up and down for 2D beings. To them, you can touch stuff, feel stuff and bump into stuff. You can hear things and smell things. All these senses would be sharpened, honed and stronger than ours since they rely completely on these senses to navigate. Now we need to look at dreams and what they are. Dreams are merely our thoughts, imagination playing around with itself when we're unconscious. So what you did during the day, and what you need to do tomorrow will have an effect on your dreams. But you experienced your day with all your senses, including vision, and thus your brain knows what seeing is. So you'll see things in your dreams. Blind people on the other hand experience their lives with all their senses, excluding vision. Therefore their imagination, and thought process will involved these senses only. Also, as explained, their brain doesn't even know what seeing is. So no, they won't see. The weird thing however, is that you see with your mind, when receptors are activated in your eyes. When you close your eyes however, you can imagine the things you saw, through your mind. So you don't sight to see in your mind. But since people who were blind from birth, haven't even activated this part at all, with them not being exposed to what it is, they can't see in their mind, since their mind doesn't know how, or what it is.