"The real voyage of discovery consists not in seeking new landscapes, but in having new eyes. " ~Marcel Proust

    Other spiritual teachers and writers would instead say you need to open your "third eye".  The basic idea is the same. 
    Since you were an infant, you have been taught to concentrate your vision on the physical.  Not only are you taught to observe the material world, but to focus your vision on the specific item of interest, for example,  if you are outside and you hear a bird singing, the immediate response is to look toward the bird and focus on it.  When you do that two things happen: one, you will probably frighten the bird, which can feel your eyes concentrating on it, and it will fly off, and two, you will miss many things going on around the bird including perhaps the reason for his joyful song.  
    There are times when focusing our vision is useful, perhaps even necessary, but there are also times when it isn't.  One of those times is when we are trying to open ourselves up to the spiritual.  Spiritual things are happening around us all the time.  Most of them are nearly invisible, and always go unnoticed when you are focusing on a physical object or being, but when you are open and alert in a spiritual sense, and you let your eyes stop focusing, you may start to notice these spiritual things.  So practice being unfocussed.  It goes against everything you are taught in materialistic institutions, but it is very useful if you want to develop spiritually.