When a ray of light travels from optically denser medium to optically rarer medium, it always bends away from the normal.
According to Snell's Law: n2n1=sinisinr
For optically denser medium, refractive index n1 is greater than that of the rarer medium n2. Thus, the angle of refraction has to be greater than angle of incidence i.e. it bends away from the normal.