A ray of light that falls at right angles to the surface of a glass block,after refaction?

After refraction, the ray of light will change direction and continue to travel through the glass block. The exact direction of the refracted ray will depend on the angle of incidence and the refractive index of the glass. However, if the ray of light falls at right angles (perpendicular) to the surface of the glass block, it will not change direction and will continue to travel in a straight line through the block without any deviation.