How is it possible for light (photons) to be Refracted?

to answer your question with my understanding the light particles or particle acts as both WAVE and a particle, in fact if you refer Stephen hawkings Brief history of time" Chapter 3 the end part

Consider a partition with two narrow parallel slits in it. On one side of the partition one places a source of fight of a particular color (that is, of a particular wavelength). Most of the light will hit the partition, but a small amount will go through the slits. Now suppose one places a screen on the far side of the partition from the light. Any point on the screen will receive waves from the two slits. However, in general, the distance the light has to travel from the source to the screen via the two slits will be different. This will mean that the waves from the slits will not be in phase with each other

when they arrive at the screen: in some places the waves will cancel each other out, and in others they will reinforce each other. The result is a characteristic pattern of light and dark fringes.

The remarkable thing is that one gets exactly the same kind of fringes if one replaces the source of light by a source of particles such as electrons with a definite speed (this means that the corresponding waves have a definite length). It seems the more peculiar because if one only has one slit, one does not get any fringes, just a uniform distribution of electrons across the screen. One might therefore think that opening another slit would just increase the number of electrons hitting each point of the screen, but, because of interference, it actually decreases it in some places. If

electrons are sent through the slits one at a time, one would expect each to pass through one slit or the other, and so behave just as if the slit it passed through were the only one there – giving a uniform distribution on the screen. In reality, however, even when the electrons are sent one at a time, the fringes still appear. Each electron, therefore, must be passing through both slits at the same time! A nice way of visualizing the wave/particle duality is the so-called sum over histories introduced by the American scientist Richard Feynman.

Thus it seems that particle of light behave both like a wave and a single particle too. and thus show the nature of wave as well particle. going through slit as a wave and going through both slits at a same time as a particle...

diffraction (ie. bends around an object) this is why longer shadows are fuzzier than shorter ones

Because particles in motion are also waves.

Watch this:

http://www.youtube.com/watch?v=DfPeprQ7oGc