"Retention of vision" is a physiological effect wherein the retina retains an image of an item (in this case, a coin) for a fraction of a second after the hand closes around the item (shiny coins work particularly well for this effect).
Of course there are various methods and versions of sleights that employ the retention of vision effect - it really can be a powerful tool when used properly. David Roth employs retention of vision to great effect and teaches his method in "Expert Coin Magic Made Easy," which can be found on DVD through L&L. Of worthy note is that his method comes straight out of the pages of Bobo.
Because of this, I recommend that you pick up a copy of Bobo. "Modern Coin Magic" is encyclopedic and many folks have found it difficult, at best, to read through. I suggest that if you get Bobo, take a look at the Bobo study guide, found starting
here. Hopefully that will help you along with the tome.
Further, I would suggest that you learn to routine your material, rather than looking for a single trick. By routining your material, you not only increase the strength of your magic tricks but you cover a great deal of what your doing by hiding it inside of layered presentation, which makes reconstruction nigh on impossible for your spectators.
As an example, you do a retention of vision vanish making the spectator believe that the coin is in the left hand, when it is actually in the right hand. You would then vanish the coin. Reaching into the air with your right hand, you pluck the coin from the air. Now, how hard is that for your spectators to realize that you simply kept the coin in the right hand to begin with? Not very hard at all.
So, hopefully, you can see that doing a single magic trick like that above is simply not very magical at all. If that trick above was part of an overall routine, however, then your spectators don't have time to analyze what has happened, becuase you are now offering them something more, keeping their attention on something new that is happening. Once finished, they will have a very hard time going back and reconstructing the various components of your overall routine.
So, learn to routine. And, routining is also taught in Bobo.
Get Bobo.
Mike.