One of the major misconceptions about visual impairments is that it means someone cannot see at all. In fact, while many people with vision problems will be said to have 20/200 vision, the actual range of sight issues they have can vary quite considerably. For some people it may mean complete loss of sight, but for others, it can mean a wide range of issues that severely restrict their vision in different ways. One of the more common of those is peripheral vision loss, which is often referred to as tunnel vision. But what is peripheral vision, what causes the loss, and how can we prevent it?