Vertical blinds can be tilted open just like a horizontal blind. By pulling the chain, the vanes, or slats, open and close to let light in, and allow you to see out. Beyond that, they actually provide more options than a horizontal blind. Vertical blinds have the ability to stack in various ways. There is the standard left or right stack, which means that when you open your vertical door blind, the slats, or vanes, all draw open to the left side or the right side. Then there is the split draw, it opens the vertical door blinds from the center, and stacks an even number of slats to both the left and right sides.